List of Agents of S.H.I.E.L.D. characters

Phil Coulson

Phillip "Phil" Coulson (portrayed by Clark Gregg) was the S.H.I.E.L.D. agent in charge of Project T.A.H.I.T.I., meant to bring a potential dead Avenger back to life using a drug derived from an ancient alien corpse. Following his death in The Avengers, Fury resurrected Coulson using T.A.H.I.T.I., and had his memories of the project replaced. Coulson puts together a team of agents, and they travel the world dealing with strange new cases. During this time, Hydra is revealed to have infiltrated S.H.I.E.L.D., leading to the latter's demise. Fury makes Coulson the new Director of S.H.I.E.L.D., and tasks him with rebuilding the agency "the right way". Coulson becomes romantically involved with Rosalind Price, the leader of an anti-Inhuman government taskforce, until her death at the hands of Grant Ward, one of Coulson's former agents. He gets revenge by crushing Ward's chest with his prosthetic hand. Following the signing of the Sokovia Accords, S.H.I.E.L.D. is re-legitimized, with the still officially dead Coulson replaced as director.

Phil Coulson was created for Iron Man; he was the first S.H.I.E.L.D. agent introduced in the MCU, and was portrayed by Gregg, who went on to play the character in several other MCU films and Marvel One-Shots. At the 2012 New York Comic Con, Gregg was announced to be starring as Coulson in Agents of S.H.I.E.L.D., despite the character dying in The Avengers." In April 2013, Gregg said that he had found creator Joss Whedon's explanation for Coulson's resurrection "fascinating" and "true to the world of the comics and mythology in general". On whether the resurrected Coulson would be the same as before he died, Gregg said "I think if he hadn’t gone through some kind of change, it wouldn’t be any good." After Coulson was promoted to Director of S.H.I.E.L.D., Gregg said "He kind of got his dream job that I don’t even think he would have ever dreamed he would be given ... it’s going to require him to move a little bit in the direction of a more pragmatic figure like Nick Fury". Discussing Coulson's character progression through three seasons, executive producer Jeffrey Bell said, "First season Coulson would have beat Ward up and then thrown him over his shoulder and brought him back to Earth and locked him away. Season two Coulson would have defeated him and left him there on the other planet to fend for himself," while season three Coulson paused while a portal to Earth was closing to take the time to kill Ward.

Melinda May

Melinda Qiaolian May (portrayed by Ming-Na Wen) is a S.H.I.E.L.D. ace pilot and weapons expert who is called "the Cavalry", against her wishes, after a mission to Bahrain where she saved an entire S.H.I.E.L.D. team from a rogue gifted—unbeknownst to S.H.I.E.L.D., she did this by killing a young girl. Still struggling to move past this event years later, May agrees to watch her old friend and partner Coulson for Fury, reporting to the latter and looking for potential side-effects of Project T.A.H.I.T.I. in the former. When Coulson becomes the new Director of S.H.I.E.L.D., May acts as his second-in-command, and over time begins to move past the events of Bahrain and even develop familial relationships with characters such as Skye.

Wen was cast as May in October 2012. Whedon had the character, who was originally listed with the name Agent Althea Rice on casting sheets, "rolling around in his head" for a long time. In preparation for the role, Wen was "given a couple of background stories" about May, but found it challenging to play a character who is respected by those around her when the audience doesn't know why, stating "It's a challenge in different ways....I use some of my own personal experience where we've been scarred or we've been greatly disappointed". When May's past was revealed in "Melinda", Wen called it "devastating", explaining "She was married, she was in love with Andrew, she had a job that she excelled at and loved and believed in—so her world was pretty perfect...To have learned what she had to do, for the good of the many...I can understand why it would traumatize her so much and cause her to retreat." May's shirt is the same blue as many S.H.I.E.L.D. agents in The Avengers such as Maria Hill, so as to have some continuity between her uniform and those established in the films. The rest of her costume is inspired by military flight suits, including a leather vest, and pants with stretch panels to aid with fighting.

Following the series premiere, Wen teased the character, saying "She's very much the observer, and whenever she wants to put in her two cents, it's something that you want to listen to and kind of pay attention to...She's slow in getting acclimated to part of the group and being in the field again." Talking about May's reasons for staying with S.H.I.E.L.D., Wen explained "May’s friendship and...loyalty and her love for Coulson [keeps her there]. Maybe not romantic [love], it’s just really—it’s hard to describe—it’s a bond, it’s unbreakable, and she will watch over Coulson and take care of him and help him through whatever he needs to at this point in his life... She wants to be there for him, and if it serves S.H.I.E.L.D., that’s just more or less a side effect, really." Wen admitted that May develops a relationship with Skye over the course of the series, going from thinking of Skye as "someone that she didn’t want as part of the team and didn’t understand why Coulson wanted her" to wanting Skye "to be the best agent that she can be." After discovering that Skye is an Inhuman, Wen stated that "it’s like when you have your child or your daughter losing control or getting involved with situations or people that you’re not sure about. You don’t have the control anymore. It’s very frightening. For Skye to be an unknown entity, May still holds out hope. She hopes that her training with her will help her be able to control her new powers, but you never know. Sometimes the power overtakes everything else."

On how May deals with her ex-husband Andrew becoming the Inhuman killer Lash, Wen said, "She's come to the understanding that it was something he had no control over. The betrayal might be not sharing that information of what happened to him with her. I think she understands that, in a way, he was scared and trying to be protective of their relationship and doing it all for the wrong reasons. I think, ultimately, Agent May is kind of shut down when it comes to Lash and Andrew at this point. That's why she's re-focusing all her energy back into S.H.I.E.L.D., back being by Coulson's side. That's where she's most comfortable." Wen went on to describe May as "unconventionally maternal...she's taking care of Simmons and really believing that she needs to be able to protect herself, she's very, very concerned about the family's well being."

Wen received nominations for 'Favorite Actress in a New TV Series' at the 40th People's Choice Awards and 'Favorite Female TV Star – Family Show' at the 29th Kids' Choice Awards. Wen was also named TVLine's "Performer of the Week" for the week of April 12, 2015, for her performance in "Melinda", specifically her portrayal of May in the flashback sequences.

Grant Ward

Grant Douglas Ward (portrayed by Brett Dalton), the son of politicians, was abused by his parents and older brother Christian growing up. After attempting to kill Christian by burning their house down, Grant meets John Garrett, a Hydra double agent within S.H.I.E.L.D., who trains Grant to be a skilled agent. Later being assigned to Coulson's team, Grant is outed as Hydra when that organisation is revealed to the world, and, after the death of Garrett, becomes a prisoner of S.H.I.E.L.D. In love with his former teammate Skye, Grant escapes custody, apparently kills Christian and their parents, and infiltrates Hydra so Skye can meet her father. Despite this, Skye turns on Ward and shoots him, and he escapes only with the help of former S.H.I.E.L.D. agent Kara Palamas, with whom he develops a romantic relationship. He accidentally kills Palamas while she is in disguise as May, and blaming S.H.I.E.L.D., decides to take over the now leader-less Hydra. Joining forces with one of Hydra's previous leaders, Gideon Malick, Ward travels through a portal to an alien planet in search of the ancient Inhuman Hive, but is killed there by Coulson. This allows Hive to use Ward's body as a host. Ward returns in the Framework created by Holden Radcliffe as Johnson's boyfriend.

Dalton was cast in November 2012. From the conception of the series it was decided that Grant Ward would be a traitor, with executive producer Jed Whedon saying "since [the events of Captain America: The Winter Soldier are] an infiltration based on betrayal on a massive scale, we wanted to have it on the small scale, and have it be a really personal dagger to the heart." Ward's initial costumes were inspired by Jason Bourne and Ethan Hunt, with his look based purely in function and with a muted color palette to reflect his serious attitude. After Ward was outed as Hydra and became a prisoner of S.H.I.E.L.D., Dalton grew a beard for the character, explaining that S.H.I.E.L.D. would not provide a prisoner with a razor, "so it just happens to work out that I have a beard and beards can have a sort of evil connotation." Austin Lyon portrays a young Ward.

Dalton has described Ward as he first appeared in the series as "a guy who is very trustworthy and rolled up his sleeves and did all the heavy lifting and didn’t really question authority. You know, a by-the-book risk assessor". Although it was eventually revealed that Ward was a Hydra imposter, Dalton noted that that doesn't necessarily mean the relationships the character built with his S.H.I.E.L.D. team weren't genuine, since going undercover meant letting his guard down to make the other characters trust him, opening himself up to those relationships despite his ulterior motives.

Following the death of Garrett, the question was asked, "Who is [Grant Ward] without someone telling him what to do?" Dalton answered that "he can follow commands really well. He can do and make tough choices and he can sometimes do unpleasant things in the name of something that he feels he believes in. But...I don’t think that Ward knows the answer to that question himself." Dalton called the character a 'wildcard', since he was loyal to Garrett as a father figure rather than Hydra, "and he was more about his teammates rather than the team", later elaborating that "It’s not quite good guy, it’s not quite bad guy. It’s not trying to get in with S.H.I.E.L.D. again, it’s not trying to get in with Hydra. He’s really on his own path. He’s living by his code at this particular point in life." Explaining Ward's relationship with Palamas, Dalton stated

When they first started this relationship, I thought they’re two people who have experienced something similar by following orders and then finding themselves not knowing who they are when someone’s not telling them what to do....But it really [has] developed into something that’s much more complicated than that. There’s a teacher-student relationship there as well as what seems like a genuinely romantic relationship. You see us really lovey-dovey in the cockpit and it’s making everybody around us sick. In some ways, we have the most healthy relationship out of all of the other dynamics on the show, which is saying something because Ward is not a lovey-dovey kind of guy. That’s interesting that he’s now in probably the most stable relationship there is.

When Ward accidentally kills Palamas in the season two finale, Dalton said that "This affects him in a way that is deep and lasting. There was a shred of humanity in there, and always the possibility and the thought that he could be redeemed...After Kara’s death—that is actually at my hands—after all the time and effort and energy that’s been invested in this relationship, it turns him. You see it in his eyes....This whole thing of closure keeps coming up over and over again. There is so much closure out there in the world that needs to be achieved. There’s a lot of unfairness that he wants to fix, so we see somebody who is determined, who knows who he is, and is like, 'Fine, if you want to call me the bad guy, I’m the bad guy.'"

Speaking about the monologue Ward gives in "Maveth", Dalton noted that some viewers thought Ward sounded like "a born-again, devout, off-my-rocker person at that point", but Dalton felt that it was "a real moment for Ward where he actually gets a sense of there's something greater than revenge and all of these smaller emotions; there's actually something that's bigger out there that he's a part of." Following Ward's death later in the episode, Bell discussed whether the writers ever considered redeeming the character, saying, "No character is too high to fall or too low to be redeemed, theoretically....but for someone to be redeemed, they need to ask forgiveness, or want to be redeemed....[Ward] never felt like he needed to apologize for what he did." Dalton returned to the series in the fourth season to portray Ward in the Framework.

Dalton won for 'Male Breakout Star' at the 2014 Teen Choice Awards. The character of Grant Ward garnered a large fan following, with a group known as the "Ward Warriors" often using the hashtag "StandWithWard" on social media. Dalton was surprised that people "seem to be standing with Ward no matter what he does....there are people out there who just seem to be following this character wherever he goes. I think that’s brilliant....There isn’t any character like him on the show, and I would say even within the Marvel canon." As a "shoutout" to these fans, Palamas says, "I will always stand with Ward" in the second-season finale, which Dalton called "a testament to the fans, this incredibly loyal fanbase that has now influenced the script of our show."

Hive

Hive (from Latin: Alveus) is one of the first Inhumans, a parasite who can connect with and control the minds of other Inhumans and feed off of or possess humans. Created by the Kree from a Mayan hunter (portrayed by Jason Glover) to lead their Inhuman army against mankind, Hive ultimately incited a rebellion, uniting humans and Inhumans to drive the Kree from Earth. Soon, a faction of Hive's followers who feared his power banished him through a portal to the planet Maveth, where he destroyed an entire civilization over centuries. He eventually only survived on human sacrifices sent through the portal by followers, and their descendants, still loyal to him—Hydra. Hive escapes back through the portal in modern times by possessing the body of Grant Ward. He retains the memories of all the bodies he has inhabited, including now Hydra leader Gideon Malick's brother Nathaniel, and punishes Gideon for causing Nathaniel's sacrifice by murdering his daughter Stephanie, before taking control of Johnson, who Ward was in love with, and using her to kill Gideon. Hive then takes steps to recreate the original Kree experiment that made him, planning to use a warhead to spread a pathogen around the world and transform all humans into Primitive Inhumans. He is destroyed when S.H.I.E.L.D. traps him in a quinjet with the warhead and detonates it in space.

Based on the Hive, "a genetic experiment created by Hydra" in the Secret Warriors comic, Hive possesses the corpses of first Will Daniels and then Grant Ward in the show, with Dillon Casey and Brett Dalton portraying the reanimated bodies, respectively. Jason Glover briefly appears as Hive's original human form, while Dalton portrays Hive's true, CGI-created Inhuman form through motion capture. On having Hive possess Ward's body, Whedon explained that Ward has "been the baddie for a while and I thought it was a nice way to escalate this character....there’s still memories in there. So there’s still an aspect of the man we came to love to hate in there, but we wanted to give it some extra juice and we wanted to give Brett one more challenge where he has to change his character."

Dalton aimed to emulate Meryl Streep's character in The Devil Wears Prada, who never spoke above "a conversational level...She didn't pound on her chest and make sure everybody knew that she's powerful, she just was." Dalton also changed his voice to represent the memories of Will Daniels and Nathaniel Malick "just a little bit. I tried to change my voice in there, I tried to change even my level of expression in there because I was supposed to be channeling somebody else entirely coming through." Dalton called the coat that Hive wears later in the third season "iconic and timeless", noting that "fashion wasn't on the forefront of [Ward's] mind", while Hive is more theatrical, "colorful without having to do much."

Hive's ultimate goal is "connection", with Dalton saying, "all these Inhumans have a purpose. Hive finds his purpose has to do with somehow connecting all of the Inhumans. What we see is Hive's attempt to fulfill what he thinks is his destiny...this desperate need to connect. Gregg called Hive "the perfect villain for this show because he carries with him the memories, desire, hatreds and agendas of Will and of Grant Ward. At the same time, he’s got a much deeper, bigger agenda that’s thousands of years old, and gave birth to Hydra." Dalton described him as a "survivor" who "does not think small. This person has been around for way too long to think in anything other than global terms." He saw this as a fundamental difference between the character and Ward, who "just becomes single minded and is hellbent on one thing at a time....Hive is the opposite. He sees every move on the chess board. That's what we're seeing in terms of Hive's thinking. It is about a new world order of sorts." On how much influence the memories of those whose bodies Hive inhabits have on the character, Dalton said, "It's the motivations...you're seeing a flash of it. It's almost like seeing your kid. There are flashes of you in there...but then again, it's not me."

Dalton realized that Hive would not be on the show for long when he took the part, with "the big, big bad" less likely to last as long as an "anti-hero" like Ward. On Hive's final scene in the third-season finale, Dalton noted that there would have been no point in the character doing anything other than reflect: "It's like looking into a fire. Somehow the truth comes out. You're looking at the Earth, man. It's so far away. And you'll get a perspective on things. For Hive, he was trying to change that entire thing and everyone who was on there....I think there's a great deal of remorse [that he was not] able to achieve that connection and do all the things that [he] wanted to do. But there was also an acceptance."

Daisy "Skye" Johnson / Quake

Daisy Johnson (portrayed by Chloe Bennet) was born in China to Calvin Johnson and his Inhuman wife Jiaying, but was soon taken by S.H.I.E.L.D. agents and raised as an orphan by nuns. Taking the name "Skye", she became a skilled hacktivist, opposing organisations like S.H.I.E.L.D. This led to her involvement with Coulson, who decided to recruit her, and have Ward, and then May, train her to be a formidable field agent. After reuniting with her father, Skye chooses to drive him away, knowing him to be a monster and murderer, though his wishes for her to fulfill her destiny—by unlocking her Inhuman abilities—are granted when she unintentionally comes into contact with the Terrigen Mists, which give her earthquake-generating abilities. Skye soon meets Jiaying, who helps Skye control her abilities. Skye's loyalties are tested when Jiaying attempts to start a war with S.H.I.E.L.D., and she ultimately sides with S.H.I.E.L.D. Now using her birth name, Johnson forms a S.H.I.E.L.D. team of Inhumans named the Secret Warriors. After briefly being connected to Hive, and watching Lincoln Campbell, with whom she developed a romantic relationship, sacrifice himself for her, Johnson leaves S.H.I.E.L.D. and becomes known as the powered vigilante "Quake" to the public.

Daisy Johnson was created by Brian Michael Bendis and Gabriele Dell'Otto for Secret War #2. When the character of Skye was introduced to the series, it was always intended that she would be the MCU version of Johnson, as executive producer Maurissa Tancharoen explained, "there are always the series of clearances, but we always knew we wanted to evolve Skye into something else. Daisy Johnson was the main character that we wanted to go for. We got confirmation on that very early on, so we’ve been on that track ever since." Bennet was cast as Skye in December 2012, out of more than 400 actresses who auditioned for the role. Unlike the comic version, Skye is an Inhuman; Jed Whedon explained that "We’ve created a different origin for her...we merged those two ideas together also because there are such rabid fans out there that if we stick to original story points from the comics, they will smell story points from miles away. Those two factors led us to coming up with a different notion of how she got her powers." During a single-shot fight sequence in "The Dirty Half Dozen", Bennet broke her arm and finished the second season without wearing a cast.

Skye's initial costume design was intended to keep her relatable, with inspiration coming from street style blogs, but as she became a more experienced S.H.I.E.L.D. agent in the second season, she received a more tactical outfit. For the third season, Bennet cut her hair to further her character's transformation to Daisy Johnson, as she is portrayed in the comics, though she did not cut her hair as short as her comic counterpart; Bennet explained that "the comic book version of Daisy Johnson has very short, Miley Cyrus-esque hair. We wanted to stay true to the comic book character fans love; I wanted to please them but also make sure there was still some movement and length and sexiness in the hair." Bennet also received a superhero costume for the third season, again bringing the character closer to the version in the comics. Foley felt that "one of the most important things was that the symbol be incorporated into her costume but especially onto the gauntlets, And it’s also on the back of her suit, which was a fun little touch that we added. As far as the silhouette, we wanted to stay true to the comics and pay tribute to those original designs. I also wanted to incorporate the gold color that I’ve seen in some of the illustrations of her suit throughout the comics, which is why we have the gold lines that we see on the suit. Finally, for me personally, I wanted a nod to her tactical look from last season, so if you look at the style lines around the top of the costume, you will see that they’re similar to her tactical hood from Season 2." The suit was "made out of printed EuroJersey, which works well for these costumes because it’s a four-way stretch that gives Chloe the ability to move and do her stunts... But there is a lot more leather in her suit than in some of the others." Legacy Effects created Johnson's iconic gauntlets from the comics, making them "out of flexible materials painted to look like metal" so as not to injure anyone during stunts.

Bennet, talking about Skye's commitment to S.H.I.E.L.D., stated that "I think at the beginning she came into S.H.I.E.L.D. thinking it was this government-run, CIA-type thing, where they’re not for the people and their motives were not good ones. But throughout the [first] season, being on the team and seeing what was happening, she really got to know why S.H.I.E.L.D. is there. It really is to protect people, and the intention behind the organization is pure....I think she finds a parallel between S.H.I.E.L.D. and Coulson, and I think that’s why she’s committed to it so deeply." Elaborating on this, Bennet said "she’s always had this unspoken bond with Coulson that’s a very father/daughter relationship where clearly the love they have for each other is evident in a very caring way."

Going into the second season, Bennet noted on the character, "I think she’s always someone who will wear her heart on her sleeve, but I think she’s much smarter about it now, if that makes any sense. I don’t think she’s the type of person who can halfass anything, and that includes emotions. If she feels something, she feels something. But she knows how to control it more". Talking about the changes to the character after it was revealed that she was Daisy Johnson and an Inhuman, Tancharoen said "With this discovery will come some consequences, especially in her relationships with everyone around her, specifically Coulson...Needless to say, it’s going to be a very complex, emotional journey for her. We have the ability on a television show to really explore the emotional journey of that. What does that mean now that she has this ability? Does she even want it?" Explaining some of these changes in the character, Bennet stated that "I make sure to try to keep the season one Daisy weaved through the new, badass Daisy....[but] she's changed a lot. She went into S.H.I.E.L.D. hating organizations like S.H.I.E.L.D., and now she's the epitome of S.H.I.E.L.D. She believes in everything that they believe in."

Discussing the character becoming leader of the Secret Warriors, Bennet said, "What makes her such a good leader is how much she's been through, so she can relate to everyone on the team and she really has so much empathy and that's what I love about playing her. She really genuinely cares about everyone so deeply and it wears heavily on her because she obviously went through this big Inhuman change...And so what I think makes her such a good kind of...unconventional leader is that she's really kind of still learning and I think that's so realistic that leaders are—it's almost like when you grow up and you realize that your parents are just humans, parenting." Wen noted how the character "has evolved from being so anti-establishment into suddenly being someone who wants to create an establishment that would help and enhance the betterment of the world", to which Bennet said, "she was lost for a really long time, she was an orphan and she wanted to find her parents and all of a sudden she does and it's not what she expected. You know, when your mom tries to kill you and your dad is Hyde. So she's kind of grown into this."

Entering the fourth season, Bennet felt that, after the events of the final episode of season three, Johnson was "in a darker place. She's mourning. She cares about the team so much that she feels like she is protecting them by kind of pushing them away, because I think she feel like everything bad happens around her and she can't help but cause problems. Her way of taking care of the people she cares about is kind of pushing them away, which... is not the best thing." She also added that physically, Johnson would not be in great shape, since she is no longer under S.H.I.E.L.D.'s monitoring "containing and helping me grow my powers" so there would be "repercussions of her kind of using these powers and... abusing her body".

Bennet received nominations for 'Favorite TV Actress' and 'Favorite Female TV Star – Family Show' at the 28th and 29th Kids' Choice Awards, respectively.

Leo Fitz

Leopold "Leo" Fitz (portrayed by Iain De Caestecker) is brought on to Coulson's team as an engineering and weapons technology specialist, and provides tech support for the team throughout the first season. He has a close bond with Agent Simmons, the two having graduated from the S.H.I.E.L.D. academy together. At the end of the first season he confesses to Simmons that he has romantic feelings towards her, before nearly dying in an attempt to save her. Left with severe brain damage, Fitz struggles with technology and speech, but over time becomes a full member of the team again.

De Caestecker was cast as Fitz in November 2012. Following injuries the character receives at the end of the first season, the series began to deal with brain trauma, as De Caestecker explained "From the get-go, before I even knew about it, the writers had the idea, and they did a lot of research in it with doctors. When I found out about it, I did my own research and correlated it together. It's just something that should never be trivialized. It's a real and serious thing to a lot of people, brain trauma, so we just have to constantly be respectful towards it. We talk about it all the time. Even if you don't see it or it's not obvious, it's always something that's in our heads that we're keeping going. It's the realization that you never get fully better, it's about embracing the new side of you and making that work in the world that you're in. I suppose the idea of a cure—I don't know if that could happen." For Fitz's costume design, Foley tried to have his clothes reflect his personality, without "getting too cliché...we try and play up his "heritage style"...using classic design details on him like paisley & leather elbow patches and mixing them with different plaids."

De Caestecker, in describing the character, said that "Fitz has got this funny kind of temper. He’s quite passionate about what he does. So those moments where—I don’t think he’s someone that really responds very quickly to emotion; he doesn’t really understand emotions as much". Fitz has a lot of interaction with Simmons in the series, with De Caestecker explaining "My character, he’s Engineering, so he’s on the computer and tech side of everything. He’s consumed within that world, and he works very closely with Simmons, who’s Biochem. They’ve got this kind of weird chemistry together, and they just kind of fit each other in a very weird way." Regarding the changing dynamic over time between Fitz and Simmons, De Caestecker said "I suppose what's happened from the start of season two up to midseason is, they've become a lot stronger as individuals, I think. But I think they still care for and need each other a lot, and they also work better together when they are together. But I think there's a lot of things that have still been unsaid and will hopefully come out, certain confrontations that are still bubbling under."

De Caestecker was named TVLine's "Performer of the Week" for the week of September 27, 2015, for his performance in "Laws of Nature", particularly the episode's final scene.

Jemma Simmons

Jemma Simmons (portrayed by Elizabeth Henstridge) is brought on to Coulson's team as a life sciences (both human and alien) specialist, and has a close bond with Agent Fitz, the two having graduated from the S.H.I.E.L.D. academy together. She grows to mistrust all things alien and superhuman, but shows her loyalty to Coulson despite this when they are faced with the rival S.H.I.E.L.D. faction. Following the fight against the Inhumans, Simmons is absorbed by the Kree monolith, a portal to the alien planet Maveth. There she falls in love with Will Daniels, who sacrifices himself so she can return to Earth. Simmons eventually moves on from Daniels, and begins a relationship with Fitz.

Henstridge was also cast in November 2012. She described her character as "a biochem expert. She’s young and hungry and she’s a great woman to play because she’s intelligent and focused and curious and she doesn’t apologize for it. She’s got a wonderful relationship with Fitz. They kind of bounce off each other." After the reveal during the season two premiere that Fitz was just imagining Simmons in the episode, Henstridge explained that the showrunners "tell you what you need to know to act your scenes, but anything after that, you never know." For Simmons' costume design, Foley tried to have her clothes reflect her personality, without "getting too cliché...we mix the hard with the soft—we combine the feminine elements like peter pan collars, silk blouses and florals with the masculine touches like ties".

Henstridge talked about the characters of Fitz and Simmons being separated over the course of the series, noting that they have "never been without each other. When you see them without each other, that brings a whole new dynamic just to them as characters in discovering what it's like to have to be independent". On Simmons' guilt over Fitz's brain damage, Henstridge said "She feels a huge amount of guilt. There’s a lot of emotions happening. A lot of it revolves around Fitz and Ward. She feels a lot of anger and resentment at the situation. When something catastrophic happens to someone you love, or a situation arises that affects people you love the most, if that’s the first time you’ve been in that position, you never really know what to do." As this relationship developed through the second season, Henstridge said, "I don't think they fully realize the implication of how far apart they are. There's so much hurt there. I don't think they realize what they're sacrificing by not figuring this out." Talking about the harsher side of Simmons seen later in the second season, after the reveal of the Inhumans and the subsequent death of Agent Triplett, Henstridge explained that at the beginning of the series, Simmons was "very mathematical" but throughout the first season "understood that it was more about human relationships and what it means to save someone's life". Now, "she's had a traumatic event and she's gone straight back to what she knows of trying to make everything black and white", and so "It makes sense [to her] if there are these people—call them what you want; Inhumans—that cause destruction, and you can get rid of them, then they won't be a destruction [sic] anymore....Of course it isn't" that simple.

After Simmons is trapped on the planet Maveth for six months, she becomes "profoundly different", with Henstridge describing her as "definitely still her essence—she doesn’t just completely change. But she’s been through so much. She’s hardened. She’s had to face things that she never would’ve imagined, also by herself without Fitz, so she’s definitely changed, stronger and kind of damaged." Describing the relationship that Simmons develops with Daniels on the planet, and comparing it to that with Fitz, Henstridge said, "It's very visceral. It's more primal and intense. That just comes from having to survive in a hostile environment, only having each other on the whole planet. The stakes are always so high, so it's more physical than her relationship with Fitz. FitzSimmons is a slow burn that's taken years and years, and they connected over intellect, whereas her and Will, it's an "us against the world" kind of thing." After Daniels dies and Simmons eventually moves on with Fitz, the latter two are shown consummating their relationship after several seasons worth of build up. "We imagine they spend the morning after laughing a lot about what just happened," said Whedon and Tancharoen, "We want their relationship to feel like their friendship did, because all the best relationships are just that. So moving forward, while this change in their friendship would hopefully only deepen their connection, it is bound also to make things a bit more complicated."

Henstridge was named TVLine's "Performer of the Week" for the week of October 25, 2015, for her performance in "4,722 Hours", particularly for carrying the episode herself.

Lance Hunter

Lance Hunter (portrayed by Nick Blood), an SAS lieutenant turned mercenary, joins post-Hydra S.H.I.E.L.D. at the request of Coulson following a recommendation from his ex-wife Bobbi Morse. Despite a tumultuous relationship with Morse, Hunter becomes a full-time S.H.I.E.L.D. agent, and risks his life to save her when she is kidnapped. Following an incident in Russia involving the near-assassination of Prime Minister Olshenko, Hunter and Morse decide to disavow themselves from S.H.I.E.L.D. to protect Coulson and the team.

Lance Hunter, created by Gary Friedrich as the British version of Nick Fury for Captain Britain Weekly, was confirmed in September 2014 to be a member of the principal cast for the second season. Blood was announced as cast at the 2014 San Diego Comic Con, where the character was described as not a S.H.I.E.L.D. agent, but a mercenary. On his character joining the cast, Blood explained that "each different character, the original characters, has a different kind of response to [Hunter]. Generally I think they’re slightly wary, a little bit suspicious, [but also] a little bit amused by him. Because the nice thing about him coming into this group is that Lance doesn’t really care that much of what people think of him. So he’s very much himself and very comfortable in it. He doesn’t bow down to the etiquette of the S.H.I.E.L.D. hierarchy."

Talking about Hunter's integration into the team following an offer from Coulson to become a full-time agent, Blood said, "I feel Hunter probably feels very independent, still, so I don't think he would like to admit that he's not an outsider, that he's a part of it....He doesn't have too much respect for authority and titles, particularly in this world, but I think he takes each decision as it comes. If Coulson does something he respects, that's all good. If he doesn't, he's going to say something. But I think he sees that [Coulson is] trying to do the right thing, and he's got a lot of respect for him in that sense". Also, on Hunter's on-again, off-again relationship with Morse, Blood said, "I think the dynamic's great. I think it's really good and there is a lot of truth in it of those relationships you have where it's kind of, "can't live with each other, can't kill each other," and that sort of thing." After Hunter kills a man in "A Wanted (Inhu)man", Blood said, "I think that’s probably newer for the audience than it is for Hunter. I think Hunter, in his past, has probably done some morally questionable acts....not to say he’s ever been a vicious, vindictive, or immoral person. I think he’s just kind of straddled that line between right and wrong."

Blood left the series following the season three episode "Parting Shot" to star in the spin-off show Marvel's Most Wanted.

Bobbi Morse

Barbara "Bobbi" Morse (portrayed by Adrianne Palicki) is Hunter's ex-wife and an agent of S.H.I.E.L.D. A founding member of the "real S.H.I.E.L.D." after disobeying Fury's orders to save hundreds of S.H.I.E.L.D. lives, she infiltrates Coulson's group for reconnaissance. Coulson sends her undercover within Hydra, where she gave up the location of Agent 33 rather than risk the lives of many other S.H.I.E.L.D. agents. She later agrees, along with her fellow "real S.H.I.E.L.D." leaders, to combine their faction with Coulson's. Ward then kidnaps her in an attempt to force her to confess to giving up 33 to Hydra, but when Morse is unrepentant, Ward sets a trap for Hunter which will see him killed in front of her. Morse takes the bullet for Hunter, barely surviving. Following an incident in Russia involving the near-assassination of Prime Minister Olshenko, Morse and Hunter decide to disavow themselves from S.H.I.E.L.D. to protect Coulson and the team.

At the 2014 San Diego Comic Con, the character of Bobbi Morse / Mockingbird, who was first introduced in Astonishing Tales #6 by Gerry Conway, was revealed to be appearing in the second season. That August, Palicki was cast as Morse in a guest role, to appear in the episode "A Hen in the Wolf House", but with the potential to return. Palicki, a comic fan, was approached by the showrunners specifically for the part, and at first hesitated to take the role, thinking "I will never be able to play another Marvel character if I go forward in this role." Palicki already had martial arts and gun training, but had to learn to use the character's signature arnis sticks, and noted similarities between Morse's fighting style and that of Scarlett Johansson's Black Widow from the MCU films. Palicki was promoted to series regular with the season two episode "Aftershocks".

In approaching Morse's costume, Foley "looked at all of her comic appearances and really wanted to try to bring elements of the look from the comics into the costume that we're doing now for the show...but we had to change it, obviously, for practicality, because it had to fit into our world. It had to have a kind of tactical feeling to it too so that it made sense in our universe. She's got rivets that are in the straps across her chest, and those are there as a tribute to the buttons that go down the side of her [most recent comics] costume". The character's comics costume is traditionally navy blue and white, which was changed to navy blue and grey for the series. Three sets of the costume were produced; two for Palicki to wear, and one for her stunt double. Foley used "lots of stretch panels" and leather to ensure freedom of movement in the character's many action sequences.

With the reveal of Morse's loyalty to the "real S.H.I.E.L.D." faction, Palicki explained that the character was "not doing anything wrong in her [own] eyes...This was a choice she made. She’s been through hell with these people. She does care about Coulson’s team. She’s torn because of Hunter and she has a soft spot for Coulson. But at the end of it, she really is a true soldier and she feels there has been a compromise and she needs to take care of it." Bell, in response to a question on whether Morse had more secrets than those revealed during the second season, stated that "she and Hunter have been keeping secrets from one another, evidently for years. And one of the things I find interesting about her is she seems to be more of an ideologue—she’s loyal to an idea—and sometimes, the short term of what appears to be betrayal or short term conflict is often because of what she views as the greater good. And that’s an interesting character to have in a world where Coulson is much more "we need to protect or save that person." Are you loyal to a person? Are you loyal to the guy in the bunker next to you? Or are you loyal to the larger concept of what we’re fighting for?"

When asked about her character potentially appearing in an MCU film, Palicki said "that was one of the things that was discussed when I was coming on for the part, and you know, we’ll see what happens. It’s such a nice world that we live in that crossover can happen so often now which in the past it never really did so, to see these worlds come together on the small screen and the big screen is really cool." Palicki left the series following the season three episode "Parting Shot" to star in the spin-off show Marvel's Most Wanted.

Palicki was named as an honorable mention for TVLine's "Performer of the Week" for the week of March 20, 2016, for her performance in "Parting Shot".

Mack

Alphonso "Mack" MacKenzie (portrayed by Henry Simmons), a S.H.I.E.L.D. mechanic under Robert Gonzales, is a founding member of the "real S.H.I.E.L.D.", and infiltrates Coulson's group with Morse. After being briefly mind-controlled by Kree technology Mack's distrust in alien and the superhuman is deepened, and he decides to leave S.H.I.E.L.D. when his fellow leaders agree to join forces with Coulson. However, following the war with the Inhumans, Coulson convinces Mack to stay, and places him in charge of all alien materials. Coulson makes Mack acting director of S.H.I.E.L.D. when he goes after Ward and Hydra.

In August 2014, Simmons joined the cast as Mack, a recurring character inspired by one that first appeared in Nick Fury vs. S.H.I.E.L.D. #3. He was promoted to series regular for the third season.

Simmons described Mack as "a big guy. That is, he has a big heart, but when it comes down to it and business has to get done, there’s another side of him that gets it done....He wants to make a difference, so that’s why he wants to be a part of this team". On the different dynamic that a mechanic brings to the S.H.I.E.L.D. team, Simmons said "I think my guy does have a little bit of a different element, [because] the other people have the stress of the everyday life or death danger situations. Mack doesn’t have that quite yet. He has the stress of getting things done because he wants to contribute, but he’s not out there in the field....They might have their quips and everything, but everything is very serious. I see that my guy brings a little bit of a different color to everything. He has a little bit more humor to him, he’s a little bit more laid back." On Mack's stance on violence, Simmons confirmed that "Mack really is a guy that does not like violence at all, but, when pushed, it’s "by any means necessary." He doesn’t enjoy it, but he’ll do what he has to do."

After Mack's allegiance to the "real S.H.I.E.L.D." faction is revealed, and as his distrust of Coulson grew throughout the second season, Simmons spoke of Mack's feelings towards Coulson: "He respects Coulson. And I think he genuinely likes Coulson. But I think he just believes that Coulson is not the right man for the job....look, I’m loyal, but if the head is going about doing things that really aren’t in our job description, and he’s using us to do things for personal reasons, and then one of my brothers dies because of it? Yeah, I have a problem. And everyone else should, too....when Coulson is in his most crazed state and on the verge of killing Sebastian Derik, no one has ever seen Coulson like that. Skye witnessed it, but she has a different relationship to him; there’s like a father/daughter thing going. So out of the whole team, I was the only one to see him like that, completely out of control. I tried to explain it to Hunter—if that happened in that instant, what’s going to happen when everything is on the line? How is he going to act?—and Hunter kind of brushed it aside. But that’s another reason why Mack is very, very deeply skeptical."

Lincoln Campbell

Lincoln Campbell (portrayed by Luke Mitchell) is an Inhuman doctor with the ability to control electric charges. He helps Skye adjust to her new life post-terrigenesis, and his later attempt to protect her from S.H.I.E.L.D. and Hydra leads to his capture and experimentation at the hands of Dr. List. Skye saves his life, and when she turns on Jiaying once realizing her true intentions, Campbell is shortly convinced to do the same. Following Jiaying's death, Campbell attempts to live a normal life, convinced that his Inhuman abilities are a curse, but is hunted by the ATCU and becomes a fugitive. He subsequently joins S.H.I.E.L.D. for protection and to be near Skye—now going by Daisy Johnson and with whom Campbell forms a relationship—and becomes a Secret Warrior. Campbell chooses to sacrifice himself to save the team and the world from Hive's plan by taking Hive and a nuclear warhead to space in a quinjet where the weapon can detonate without affecting Earth.

Mitchell was introduced as Lincoln Campbell, a recurring character, in the second season. He was promoted to series regular for the third season. Regarding the character's introduction, Bell stated that "Meeting Luke’s character in the Inhuman world is just setting up a new dynamic. We’re taking Skye into a group with a whole bunch of different people. So far, we’ve seen that there’s a guy with no eyes, and there’s a woman who now is covered in thorns. And as in the X-Men world, there are a handful of people who look more like them, but a lot of them turn out to be just attractive people with powers. And we thought, "Hey, let’s have some of those as well!" We were looking for a new character to come on, and Luke just really impressed us. He was a good actor, had a nice quality, and we felt he might be a good person to sort of usher Skye into this other world."

Heading into season three, Mitchell explained that "the Lincoln that the audience was introduced to in season two was a side of Lincoln, and that side of Lincoln was not necessarily a lie or the truth or whatever, but we all put on different faces in different environments...I think in that environment Lincoln was very much under the spell of the Inhuman Elders. He played his part in the hierarchy there and he believed in the cause, which then was exposed to be evil. Then in season three, it’s like, wow, how is he dealing with the events in season two?" On seeing Lincoln's darker side in the third season, Mitchell said, "I think we’re going to see a lot more of Lincoln’s issues with his past pop up, in particular possibly some anger issues that have been unresolved. They pop their heads up from time to time. Certainly in matters of conflict, in pressure situations".

On the relationship that Campbell develops with Johnson, the only person who can "keep him somewhat in check when it comes to his anger", Mitchell said, "he wants to make something of his life, but he doesn’t see anything without Daisy in the picture", and "if something were to happen to Daisy, I think Lincoln wouldn’t stay in S.H.I.E.L.D. Daisy is his life. He’ll do anything to get her back." This is seen when he agrees to wear a "murder vest" as a fail safe, and when he disobeys orders to test an experimental antitoxin on himself—"Once he does that, and it doesn’t work, then they put him in the containment module for his own benefit, because his immune system is done. It becomes incredibly frustrating." Mitchell added, "He makes these decisions, but you still see the fear in him when he does this. It’s not just bravado....There’s a deep well of emotion in him."

The episode "Bouncing Back" opens with "a mysterious flash-forward to three months in the future, showing an unidentified S.H.I.E.L.D. agent seemingly dead in space", leading to a "four-episode event" for the final episodes of the season, marketed as Agents of S.H.I.E.L.D.: Fallen Agent. A poster created by Greg Land for the event recreated the cover of the "iconic" The Amazing Spider-Man #121 that served as the first issue of the story arc "The Night Gwen Stacy Died", and ahead of the season finale, Marvel released a series of videos that "memorialized" each of the potential character who could have been the Fallen Agent. The final episode of the season reveals that it is Campbell who dies, which the executive producers had known going into the season when forming the arcs for Lincoln, Daisy, and Ward. Bell said he "earned it", adding that Lincoln comes to a point where he realizes what his purpose is, with Whedon explaining that the decision was based on the fact that the series did not "want to be a body count show, but it is a real world with real stakes. What we had not done is the heroic death and the full-sacrifice death. This was a conscious decision. We also think that there’s a poetry in the fact that the person doing it doesn’t consider himself a hero. That’s the beauty of the moment—it’s not just for [Daisy], but it is, and it’s not just for him, but it is."

Holden Radcliffe

Holden Radcliffe (portrayed by John Hannah) is a transhumanist who believes in the improvement of humanity through enhancement. Due to his studies of parasites, Fitz and Simmons seek his help with counteracting Hive's abilities, but he is kidnapped by Hive first to help recreate the original Kree experiment that created the Inhumans. After a S.H.I.E.L.D. raid on Hive's base, Radcliffe escapes and agrees to cooperate with Coulson and Talbot. After being acquitted, Radcliffe transfers his artificial intelligence AIDA into a Life Model Decoy (LMD), an old S.H.I.E.L.D. project, which Radcliffe also names Aida. After seeing pages from the Darkhold, Radcliffe begins using his LMDs, including Aida and a decoy of May, to try and take it for himself in an attempt to learn the secret to eternal life. Fearing for his safety, Radcliffe also creates a decoy of himself, and seeks protection from the Watchdogs. Using the Darkhold and the resources of the Watchdogs' Superior, Racliffe creates an entire digital world within the Framework. Feeling that Radcliffe may one day jeopardize the Framework himself, Aida slits Radcliffe's wrists and uploads his mind to the Framework as his body dies.

Hannah recurred as Radcliffe during the end of the third season, before being promoted to the main cast for the fourth season. On Radcliffe transferring his artificial intelligence AIDA into a Life Model Decoy, Whedon said, "Radcliffe has a good heart, but he's willing to do anything for science. He's excited about the prospect. He said Fitz and Simmons had friends die and maybe they didn't have to. He's clearly opening a box. Whether or not it's Pandora's box, we'll see. He thinks there's something beyond humans." Tancharoen added, "To someone like Radcliffe, he might believe that to be just the next step in human evolution. There are a number of people who are into body modification now, so what does that mean? What's the root of that?"

Hannah felt portray Radcliffe was "quite interesting", describing him as "someone who is not the up-down, white-hearted good guy" but still is not "a bad guy". He also noted the fatherly feelings Radcliffe has towards Aida, stating, "possibly as [their relationship] develops, as she proves there’s almost a paternal... caring and sympathetic way in which that technology has developed self-awareness and how that self-awareness disappoints. A bit like you would with a child, where a child becomes aware of their own limitations, their own lackings. I would say there’s certainly have a very benign kind of deity sense about it – a benign…not dictatorship about it, but a benign parental way about it."

Recurring characters

The following is a list of guest characters that have recurring roles throughout the series. The characters are listed by the MCU media or season in which they first appeared.

Gideon Malick

Gideon Malick (portrayed by Powers Boothe) is a former member of the World Security Council and secret leader of Hydra who ascended to power following the death of his father in 1970. Gideon was joined by his brother Nathaniel, but the two soon learned of a trick their father used to avoid being sacrificed to Hive, and when Gideon followed suit, Nathaniel was sacrificed. Gideon successfully opens the portal to allow Hive to return to Earth, but Hive reveals that he has retained Nathaniel's memories, and punishes Gideon by murdering his daughter Stephanie. After being captured by S.H.I.E.L.D., Gideon cooperates with Coulson against Hive. Gideon is murdered by Johnson while she is controlled by Hive.

In October 2015, it was announced that Boothe was joining the series as a recurring character early in the third season, reprising his role from The Avengers (where he was credited only as "World Security Council"). On how much the series would use the character later in the third season, following the midseason finale, Whedon stated that "we’d be fools not to use him more. We couldn’t be bigger fans of [Boothe's] portrayal of the role. We knew going in that we were going to get some bang for our buck, and we’ve been loving writing the character. We love the way he’s attacking the scenes. We plan on keeping him around, because we’d be idiots not to." Cameron Palatas portrays a young Gideon Malick.

Mike Peterson / Deathlok

Mike Peterson (portrayed by J. August Richards) is an ordinary man that was artificially enhanced with the Extremis-containing Centipede serum by Project Centipede. Peterson later joins S.H.I.E.L.D, but is caught in an explosion and awakens without his right leg and under the control of the "Clairvoyant", who gives him a bionic prosthetic limb as part of "Project Deathlok". After the defeat of Centipede and the "Clairvoyant", Peterson works for Coulson covertly, and aids in the take down of Hydra leader Dr. List.

Richards appeared in Joss Whedon's Angel as Charles Gunn before being cast as Peterson, who was revealed to be the MCU version of Deathlok in January 2014. Created by Rich Buckler and Doug Moench in 1974, Deathlok has gone through many different iterations in the comics. Richards called the role "a dream come true", and described the character's costume and makeup, which took "about five departments...two hours to do the makeup and then [about] 15 or 20 minutes to get into the costume", as "restrictive. I love the costume and it really helps me to play the character, because it makes me feel part-machine, part-human." The costume also had to be enhanced with visual effects, including the addition of a robotic leg and an arm mounted rocket launcher, as well as a half metal plated skull with robotic eye for when Deathlok is seen with x-ray vision. The costume was updated and evolved to be closer to the comic version for Deathlok's appearance in the second season.

Richards found "the theme of Deathlok [to be] about deep, internal conflict, and that's what we're bringing with this [version]." After returning late in the second season, Richards looked back, and felt that his initial awkwardness and reluctance with the character and the costume reflected Peterson's own journey becoming Deathlok. He also noted that when the character says "Mike Peterson is dead", "the only way that line could have meaning [is] if it were not true. I always think of Mike Peterson being at the core of this character, and whatever happens as a result of that, is all Mike Petersen."

Ian Quinn

Ian Quinn (portrayed by David Conrad) is a wealthy industrialist/philanthropist and the CEO of Quinn Worldwide, who is involved with The Clairvoyant. He acquires Deathlok technology for Mike Peterson, and attempts to sell more Deathlok soldiers to the U.S. military. After Garrett is defeated, Quinn goes into hiding with his gravitonium.

Raina

Raina (portrayed by Ruth Negga) was raised by Calvin Zabo, and grew up with stories of her heritage as an Inhuman, and her potential to be more. Becoming the Project Centipede recruiter due to her interest in powered people, Raina works with Hydra in an attempt to replicate the GH-325 serum that was used to resurrect Coulson. She eventually goes through Terrigenesis, gaining the power of precognition, but also a monstrous appearance. Raina comes to accept her new circumstances, and later allows Jiaying to kill her so that Skye can learn of the former's true intent.

Negga was first cast as a guest star in October 2013, with executive producer Jeffrey Bell later explaining that "Ruth Negga showed up and we just fell in love with her and found ways to use her beyond our initial conception". Foley was informed of Raina ahead of time, allowing her to flesh out the character with illustrations, as well as print specific fabric. When Raina is introduced in "Girl in the Flower Dress", Foley and Negga "wanted to show a progression in her dresses that reflects where her character might be going", with her initially unclear intentions paired with "a softer silhouette" and a pattern of white with black flowers. For her second appearance in the episode, "it's becoming clear that she has an agenda" so the dress is more streamlined, and the colors are flipped to black with white flowers. For her final appearance in the episode, her dress is red with black flowers. Foley concluded, "By the time you see her again in ["The Bridge"] you know she means business". After Raina is transformed in the second season she hides her hideous appearance with a hooded jacket, which Foley subtly added a flower pattern to, as "she was always going to be the girl in the flower dress, so I wanted to pay tribute to that".

Raina's Inhuman look was created by Glenn Hetrick of Optic Nerve Studios. To get to the final look, the writers spent a lot of time discussing what her transformed look would entail, such as if she would have a nose, or a tail, with series writer Drew Greenberg eventually suggesting thorns. With the design idea in hand, Hetrick and his team began compiling potential designs for the character, looking to the Clive Barker film Nightbreed, specifically the character Shuna Sassi, because "She’s a creature covered in porcupine quills and that image is so strong — it creates such a striking silhouette". Since Hetrick and his team did not have source material to pull from in the comics, he wanted to "make her feel like the first real Inhuman" and give her face a level of symmetry. When creating the prosthetic makeup, which was done in two weeks, the producers wanted to still be able to see Negga's eyes, with Bell saying, "Ruth Negga has amazingly expressive eyes and eyebrows. And she gets so much of who Raina is through the eyes. We wanted her to still be able to communicate, we still wanted you to feel her expressions through all of [the makeup]."

Victoria Hand

Victoria Hand (portrayed by Saffron Burrows) is introduced as the high-ranking S.H.I.E.L.D. agent who runs The Hub, a S.H.I.E.L.D. base. After discovering that Hydra exists within S.H.I.E.L.D., Hand turns on Coulson, believing him to be a double agent. However, Garrett soon reveals himself to be the traitor, and Hand works with Coulson to detain him. She is killed by Ward when he reveals himself to be a member of Hydra to save Garrett from imprisonment.

In November 2013, Burrows was announced as playing Hand, who was created by Brian Michael Bendis and Mike Deodato, and played an integral role in their Dark Avengers comic book series. The character was intentionally introduced in the first season as a mislead for the true identity of the Clairvoyant. With the introduction of Lucy Lawless as Isabelle Hartley in the second season, the executive producers considered establishing a relationship between Hand and Hartley, since the comic book-counterpart of Hand was in a relationship with a character called Isabelle, but Tancharoen stated that "it started to be irresponsible if we addressed it to not address it with more weight and time and energy." However, this relationship was later hinted at onscreen in "One Door Closes".

Davis

Davis (portrayed by Maximilian Osinski) is a S.H.I.E.L.D. agent who worked alongside Phil Coulson's group on investigating the explosion at StatiCorp's Particle Accelerator Complex before the Hydra Uprising. He later returned to S.H.I.E.L.D. when Jeffrey Mace became its director.

Anne Weaver

Anne Weaver (portrayed by Christine Adams) is the director of the S.H.I.E.L.D. Academy of Science and Technology who joins the leadership of the "real S.H.I.E.L.D." following the fall of the original organization, in which she fought one of Hydra's enhanced soldiers, developing a distrust in the superhumans. She takes over command of the S.H.I.E.L.D. warship The Iliad following the death of Robert Gonzales.

John Garrett / The Clairvoyant

John Garrett (portrayed by Bill Paxton) was a S.H.I.E.L.D. agent who was left for dead by that organization, and only survived by becoming the first Deathlok. Joining Hydra, he became "The Clairvoyant", leader of the Centipede group, and was focused on discovering the secret to Coulson's resurrection given the impending failure of his now outdated Deathlok technology. Under the guise of a S.H.I.E.L.D. agent tasked with capturing and interrogating Ian Quinn, Garrett joins in Coulson's efforts to find the GH-325 drug. Based on his findings, Raina is able to synthesize a version of the drug, which does save his life. However, after Hydra is revealed to have infiltrated S.H.I.E.L.D. and Garret is outed as the Clairvoyant, Coulson kills him by disintegration.

In December 2013, "a high-level S.H.I.E.L.D. agent/munitions expert who has past ties to both Coulson and Ward" was set to be added to the series. The next month, Paxton was cast as Agent John Garrett, "a rough-and-tumble former cohort of Agent Coulson with a little bit of attitude and cigar-smoking swagger". Garrett was first introduced by Frank Miller and Bill Sienkiewicz in Elektra: Assassin. Jed Whedon said that "We actually discussed Bill Paxton in the room, when we were talking about the character ... Then when he came up as an actual possibility, we couldn't believe it." Following the revelation that Garrett was The Clairvoyant, Paxton said, "He’s felt like he’s found a true home in Hydra, which is more of a Darwinian outfit. It’s survival of the fittest. He can relate to that."

Antoine Triplett

Antoine Triplett (portrayed by B. J. Britt) worked with Garrett until the Hydra reveal, after which he joins Coulson's team. Trip perishes when he becomes trapped in the chamber Skye and Raina undergo Terrigenesis in and gets hit by a fragment of the Diviner.

In December 2013, "an African-American agent who specializes in combat/weapons" was set to be added to the series. In February, Britt was announced as cast in the role of Triplett. Britt's smile and charm were incorporated into the character after he had worked with the writers for several episodes, with Tancharoen saying to Britt "I love your smile. We have to incorporate the smile of Trip into the show." Britt said of the character, "Trip likes to make sure everything is in order...he’s going make sure that stuff doesn’t go wrong. [But] I still feel like Trip has something to prove. That’s going to cross over to the second season where Trip wants to show Coulson that he can trust him."

Glenn Talbot

Glenn Talbot (portrayed by Adrian Pasdar) is a United States Air Force colonel and later brigadier general who hunts active S.H.I.E.L.D. agents after the organization's disbandment. Coulson earns his trust over time, and the two soon enter an agreement in which S.H.I.E.L.D. provides the government with sensitive assets and helps with the take down of Hydra in exchange for being left alone. He is made head of the Advanced Threat Containment Unit (ATCU) following the death of Rosalind Price, an arrangement which sees him reluctantly working for Coulson.

Created by Stan Lee and Steve Ditko for Tales to Astonish #61, Talbot was a recurring antagonist of the Hulk. Pasdar was cast as Talbot by March 2014, with this version focused on taking down Hydra.

The Koenigs

Eric, Billy, Sam, and Thurston Koenig (portrayed by Patton Oswalt) are identical brothers. The former three are S.H.I.E.L.D. agents, programmers in the initial S.H.I.E.L.D. LMD program. Eric is stationed at the Providence base and assists Coulson in the wake of Hydra's emergence, but is soon killed by Ward. Coulson and his team meet Billy, the brother of Eric, at the Playground base soon after. Billy and Sam work with Coulson on the mysterious Theta Protocol, the maintenance of a S.H.I.E.L.D. helicarrier for use by Nick Fury. Later, Coulson entrusts the Darkhold to Billy and Sam, who hide the book in the Labyrinth, a S.H.I.E.L.D. base only accessible by the Koenigs.

Oswalt joined the series as Eric Koenig in March 2014. This version of the character is loosely inspired by one that first appeared in Sgt. Fury and his Howling Commandos #27. Oswalt also portrays Eric's brothers. After previously working on Joss Whedon's Dollhouse and being a long time fan of Marvel, Oswalt was sought for the part specifically.

Calvin Zabo

Calvin Johnson (portrayed by Kyle MacLachlan), a young doctor, met the Inhuman Jiaying while in China. The two eventually married, and had a daughter, Daisy. After Jiaying was torn apart by Hydra, and Daisy was taken by S.H.I.E.L.D. agents, Cal stitched his wife back together, found innocent people whose life-force was used to bring Jiaying back to life, and began searching for his daughter, at some point changing his last name. He also began experimenting on himself in an attempt to be stronger, blaming himself for not protecting his family. Jiaying eventually abandoned the search to live a peaceful life with other Inhumans like her, but Cal continued, eventually meeting Daisy—now going by Skye—and over time forming a bond with her, despite her hatred for his past actions. Coulson later convinces Cal that Jiaying is a monster who has forced him to do terrible things, and when Jiaying starts a war with S.H.I.E.L.D. that leads to a face down with Skye, Cal kills Jiaying. S.H.I.E.L.D. then wipes Cal's memory to allow him to live a peaceful life.

During the first-season finale, Skye's father is briefly seen from behind, portrayed by a stand-in. In August 2014, MacLachlan was cast in the role, to recur throughout the second season. Initially referred to as "The Doctor", his character was revealed to be Calvin Zabo, also known as Mister Hyde, in December 2014. Zabo was created by Stan Lee and Don Heck for Journey into Mystery in 1963, and is influenced by Robert Louis Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde. MacLachlan's makeup for his transformation into the Mister Hyde persona in the second-season finale took around two and a half hours to apply. Following the conclusion of season two, Bell said on Cal's storyline, "He got to live a happily ever after in a beautiful way. We would never write off the idea of finding more story for him down the road, but we had a great time with Kyle this year and feel like that was a story that ended nicely." Bell elaborated that they "felt like everything he did came from the right place but that he was just a really horrible, broken man. The idea of [using] the T.A.H.I.T.I. program to reset him as the good person that has always been in there was too good to pass up."

Daniel Whitehall

Werner Reinhardt (portrayed by Reed Diamond), a high ranking Nazi officer and an elite member of Hydra in 1945, was experimenting on the Diviner when his base was taken by the SSR and he was imprisoned for life. Released by Alexander Pierce in 1988, Reinhardt discovered that a woman unaffected by the Diviner, Jiaying, had apparently not aged in four decades. Dissecting her, Reinhardt discovered the secret to her youthfulness and used it to de-age himself. Taking the name Daniel Whitehall, he became the North American leader of Hydra following Pierce's death, fighting against Coulson's S.H.I.E.L.D. while remaining interested in the Diviner and other alien matters. He is killed by Coulson while trying to unlock the true power of the Diviner.

At the San Diego Comic Con in July 2014, Diamond was announced as portraying Daniel Whitehall, also known as the Kraken in the comics, where he was introduced by Jonathan Hickman for Secret Warriors #7. Diamond previously worked with the creators on Dollhouse and Much Ado About Nothing, and though they had wanted him for parts throughout the first season, he had been unavailable due to commitments to another series. Diamond accepted the role of Whitehall with just 24 hours to prepare, during which he formed the character's German accent to use for flashback sequences. In developing the character, Diamond watched Nazi documentaries, and re-watched Marvel's films, looking at the characters of Loki and Red Skull in particular. From the former, Diamond was inspired by his The Avengers quote, "I am burdened with glorious purpose", as he had never played a super villain, "someone who really believed that they were the best person to rule the universe, or at least the Earth." For Hugo Weaving's portrayal of the Red Skull, Diamond looked at his anger and voice to see "how [Whitehall] would fit in within that spectrum", and settled on "this is TV. I’m the smiling, calm, villain." Diamond also sought advice from Malcolm McDowell, who told him to "Always smile and let the lines do the work." The character is often seen cleaning his glasses, an "identifying quality" devised by Jed Whedon.

Sunil Bakshi

Sunil Bakshi (portrayed by Simon Kassianides), the right-hand man to Whitehall, is instrumental in the brainwashing of Hydra's subjects, including S.H.I.E.L.D. agent Kara Palamas, who later gets revenge by brainwashing Bakshi herself. Now loyal to Palamas and Ward, Bakshi sacrifices his life to save the latter when Simmons tries to kill him.

Kassianides, a fan of the series and of comic books in general, was cast in the "major recurring role" of Bakshi in July 2014. The producers intended for Bakshi to be killed off in the fifth episode of the second season, but changed their minds after Kassianides' early table reads and extended his run on the show through to the nineteenth episode. Speaking of the character's relationship with Whitehall, Kassianides explained, "Bakshi really feels he can act under the authority of Whitehall on his own, using his own judgment. He has the trust of Whitehall and is acting as he sees fit, the consequences of which will play out." On Bakshi's motivations and thought process, Kassianides said "When you’re that committed to any ideology, I think that it allows for elements of insanity ... whether that’s been trained in him or it’s inherent, it’s not clear, but he’s certainly at that point where hurting people, torturing people, and operating under this ideology is something he quite enjoys."

Kara Palamas / Agent 33

Kara Palamas (portrayed by Maya Stojan) was a S.H.I.E.L.D. agent betrayed to Hydra by the then undercover Morse and subjected to brainwashing by Bakshi and Whitehall. The now Hydra-loyal Palamas used a nanomask to take on the appearance of May, and when the latter electrocutes Palamas whilst in this disguise, she is left stuck as May, but deformed. After Coulson kills Whitehall, Palamas works with Ward, the two forming a romantic relationship while the latter does everything in his power to bring Palamas "closure". They get her nanomask repaired so that she can become whoever she wishes, brainwash Bakshi, and kidnap Morse in an attempt to force a confession out of her. When May and Hunter come to rescue Morse, Ward accidentally kills Palamas while she is in disguise as May.

While Stojan portrays Palamas, the character is also portrayed by other cast members, including Ming-Na Wen and Chloe Bennet, when she takes on the appearance of their characters. Stojan had to balance working on the series with her concurrent recurring role on Castle, but was still able to appear in every episode offered to her. Speaking about portraying Palamas, and the differences between her and May, Wen said, "not only did she lose her face, she lost her will, really. I mean she is completely controlled by Whitehall and...it’s sort of a sad character for me to portray because she’s so opposite from May. May is so confident and knows exactly what she needs to do and can get the job done based on her own opinions and with Agent 33, not only is she disfigured, not only doesn’t she have her face anymore, she doesn’t have her identity anymore." After Palamas breaks free of her brainwashing and joins Ward, Stojan said of the character and their new relationship, "That love/romance that she has with Ward...she's really, I think, trying to find herself—whether it's good or bad. She truly believes in that one man, and she's going to follow him."

Jiaying

Jiaying (portrayed by Dichen Lachman) is the Inhuman wife of Zabo, and Daisy's mother, who does not age and can heal rapidly thanks to an elder of her village giving their life each year. Pieced back together by Zabo after Whitehall dissects her to discover the secret to her abilities, Jiaying is never the same, and goes to great lengths to find her daughter, now willingly taking innocent lives to feed her abilities, having no regard for humans. Eventually Jiaying tries to escape this new persona by founding Afterlife, a haven for Inhumans, and when Daisy (going by Skye) journeys to Afterlife, Jiaying happily becomes her mentor. However, when S.H.I.E.L.D. discovers the location of Afterlife, Jiaying starts a war with them, and attempts to kill all humans with artificial Terrigen crystals. She even tries to drain Skye's life when the former turns on her, but is stopped by Zabo, who kills her.

Speaking about the levels of violence depicted in the series, Bell admitted that the executive producers and the network did question the graphicness of the sequence where Jiaying is dissected by Whitehall, but that it was ultimately kept as is because they felt that "it was important for you to understand how horrible that was and what she went through and miraculously survived—that was a big part of our story." For Jiaying's costume, Foley "wanted her to have an other-worldly kind of feeling and then also, at the time, Dichen [Lachman] was pregnant, so we needed to come up with a silhouette that could hide the pregnancy, and kind of grow with her which is why we landed on that tunic. The great thing about it is that it had this really cool Asian feeling to it with the high neck and the buttons down the front." Foley chose the fabrics for Jiaying's tunics based on what was going on in the story and how she felt the character was thinking.

In regards to Jiaying's perceived role as the main villain of the second season due to her actions in the final episodes, Bell said "In our minds, [Jiaying] wasn’t a villain so much; she was an antagonist, but if you look at why she feels the way she does, Jiaying really earned that position." After the character's backstory and motivations were revealed, she was compared by some to the Marvel Comics character Magneto. In response to this, Bell said "We didn’t consciously mimic [Magneto], but what they both have in common is a valid motive. Jiaying was ripped to shreds...I feel like her motive is really earned in the same way that Magneto’s is fairly earned. We always want our antagonists to have good motives...We tried to make everything she says be true."

Gordon

Gordon (portrayed by Jamie Harris) is an eyeless Inhuman with the ability to teleport and emit force fields. His transition to an Inhuman was tended to by Jiaying, and he remained loyal to her in his adult life, ensuring that only a select few could enter and leave Afterlife, and joining with her in her war against S.H.I.E.L.D. While trying to spread Terrigen mist through the ventilation of The Iliad, he is killed by Fitz.

Andrew Garner / Lash

Andrew Garner (portrayed by Blair Underwood) is May's ex-husband and a psychologist at Culver University who assesses gifted people for S.H.I.E.L.D. Following a vacation with May to try and rekindle their relationship, Garner is exposed to Terrigen which unlocks Inhuman abilities within him; he becomes the monstrous Lash (portrayed by Matt Willig), who uses energy abilities to hunt and kill 'unworthy' Inhumans. Garner surrenders himself to S.H.I.E.L.D. before the transformation becomes permanent, and manages to say goodbye to May before completely becoming Lash. S.H.I.E.L.D. then send Lash to fight Hive, hoping that his Inhuman purpose is to destroy the latter. Though this is not the case, Lash is able to purge Daisy Johnson of Hive's control, before being killed by Hellfire.

In December 2014, Underwood was revealed to be cast as Garner for multiple appearances starting in the second season. In July 2015, the Inhuman Lash, who was created by Charles Soule and Joe Madureira for Inhuman #1, was announced as appearing in the third season. That August, Willig was revealed to be cast as Lash, with Hetrick again working alongside the series' makeup and visual effects teams to realize the character's "unique look" from the comics. Whedon noted that it would be their "own take on [Lash]. There will be some elements from the comics for sure, but as we always do...we’re changing it up a little bit." Bell elaborated that "it’s hard to have a hidden or magical city" in the MCU, such as Lash's comic home of Orollan, but "Lash’s agenda can certainly remain true to what it was in the comics", with him judging whether Inhumans are worthy. Willig's Lash make-up initially took six hours to apply, but the make-up team was able to reduce the time to four and a half hours.

Whedon noted that the series already has several Inhumans who are "fairly attractive" and the producers wanted "to also show the other side of the change that bad things can happen", with Tancharoen elaborating that "on a very basic level, we were interested in putting a monster in the mix, because he is not human and his looks are pretty crazy and scary. We wanted to put our team up against something like that." On how the cast and characters react to seeing Lash, Bennet said, "I like to think that they've seen their fair share of crazy shit and that's just something that's pretty insane but not totally mind-blowing." Following the reveal that Lash still had a human form, Bell said that they would spend time exploring different characters as potential candidates, though the human form was revealed to be Garner two episodes later. For the onscreen CGI transformation from Garner to Lash, Underwood and Willig were 3D scanned (the latter while in full prosthetics and make-up), and then Underwood provided motion capture for the sequence, as visual effects supervisor Mark Kolpack noted the lack of resemblance between Underwood and the final Lash design, and so wanted to keep as much of Underwood's "essence" throughout the transformation process as possible. Underwood portrayed the transformation as "painful", "rigid", and "tiring", though he noted that it would become easier for the character to transform the more it happened.

Going into the third season, Underwood had only known that the producers wanted to explore more of Garner's personal life, after his appearances in the second season were "as an appendage to Agent May...a device and a construct to open her up and see more of her life." He also did not see the Lash reveal coming, which he did not learn until the table read for "Devils You Know", when it is presumed Garner is dead, and the producers approached him afterwards to tell them their plan for the character. Underwood compared the Garner / Lash dynamic to Jekyll and Hyde and Bruce Banner / the Hulk, and compared the new May / Garner dynamic to Beauty and the Beast. On Lash's motivations, Underwood stated that "Lash sees [the Inhumans] as an exalted society and it's an honor to be an Inhuman. Not everyone is worthy of that moniker. He takes it upon himself to be judge, jury and executioner of who is worthy of being an Inhuman and who is not." Elaborating on this and Garner's connection to Lash, Underwood said, "If you look at his work as a psychologist...in S.H.I.E.L.D., he determines [who] is worthy and is not worthy to be part of the Secret Warriors team...it makes sense that it's kind of that same kind of rationale, but on steroids".

Robert Gonzales

Robert Gonzales (portrayed by Edward James Olmos) is an elderly S.H.I.E.L.D. agent, tactician, and the commander of The Iliad during the fall of S.H.I.E.L.D. who is tasked with protecting the Kree monolith. He is convinced not to destroy the ship (to prevent Hydra from claiming the monolith) so that the hundreds of agents on board may live, disobeying Fury's orders, and subsequently becomes a founding member of the "real S.H.I.E.L.D." alongside Anne Weaver, Tomas Calderon, and Agent Oliver. He remains distrustful of secrets and all things alien, even after agreeing to keep Coulson on as Director of a new, unified S.H.I.E.L.D., but still attempts to negotiate with Jiaying and the Inhumans peacefully. However, Jiaying kills Gonzales and shoots herself, claiming that he attacked her, in order to start a war against S.H.I.E.L.D.

It was announced in January 2015 that Olmos would be joining the series as Robert Gonzales, with Olmos describing joining the MCU one of the high points of his career. Concerning the apparent difference in philosophies between Gonzales and Coulson, Olmos explained that "the situations that I’ve come across and the situations that he’s come across have changed our ability to work with the same understanding. He’s working like Fury worked and under that understanding. I don’t work under Fury’s understanding....I think that Coulson’s philosophy is the same as mine! We are S.H.I.E.L.D. We are not anything but S.H.I.E.L.D. people. It’s just that our S.H.I.E.L.D., the one that we originally put forth, was very, very transparent. And the S.H.I.E.L.D. that has materialized under Fury—and now Coulson—is much more secretive." Olmos also compared the relationship between the two factions of S.H.I.E.L.D. to that between the Democrats and the Republicans.

Alisha Whitley

Alisha Whitley (portrayed by Alicia Vela-Bailey) is a duplicating Inhuman who was loyal to Jiaying until she learned that the latter started the war with S.H.I.E.L.D. After Jiaying's death, Alisha helps S.H.I.E.L.D. until she falls under the influence of Hive. She is later murdered by a Kree reaper.

Kebo

Kebo (portrayed by Daz Crawford) is a member of Hydra, second-in-command to Ward until he is killed by Morse. Crawford only signed on for the second-season finale, but the writers liked him in the character and so brought him back for the third season. Crawford said that Kebo has reservations about Ward as a boss, but "some people like their bosses, some people don’t."

Rosalind Price

Rosalind Price (portrayed by Constance Zimmer) is the head of the ATCU as it crosses paths with S.H.I.E.L.D. in the hunt for Inhumans. After developing a romantic relationship with Coulson, Price is killed by Ward.

In July 2015, Zimmer was cast as Price, who Gregg described as "a potent...I wouldn’t say doppelganger, but she’s definitely got a lot in common with Coulson. She represents a character who’s not someone he comes across every day, who has more in common with him than most other people do." That September, Bell elaborated, "Where in the past, Coulson frequently plays sort of a paternal role on the show, because Daisy is kind of a surrogate daughter figure—suddenly there's another adult [in Price], who can banter, who can hold her own, and there's something nice about seeing him in that relationship."

Luther Banks

Luther Banks (portrayed by Andrew Howard) is an ATCU agent and former Marine loyal to Price. He is killed by Giyera.

Joey Gutierrez

Joey Gutierrez (portrayed by Juan Pablo Raba) is an Inhuman and former construction worker with the ability to melt certain metals who is recruited by S.H.I.E.L.D. for Daisy Johnson's Secret Warriors team.

Raba was announced as cast in August 2015. Scott Meslow of Vulture and Oliver Sava of The A.V. Club, reviewing the season three episode "Laws of Nature", both indicated their pleasure in seeing Gutierrez, a gay character, appear on the series, which Meslow noted appeared to be the first openly gay character in the MCU.

Werner von Strucker

Werner von Strucker (portrayed by Spencer Treat Clark) is the son of Hydra leader Wolfgang von Strucker, who is recruited to Hydra by Ward after Wolfgang's death. After failing to follow Ward's orders to kill Garner, Werner is left in a vegetative state by Kebo, and is taken into S.H.I.E.L.D. custody.

Giyera

R. Giyera (portrayed by Mark Dacascos) is a telekinetic Inhuman and head of security for the ATCU, secretly loyal to Malick. He is eventually swayed over to Hive's side, until he is killed by Fitz.

Elena "Yo-Yo" Rodriguez

Elena Rodriguez (portrayed by Natalia Cordova-Buckley) is a Colombian Inhuman who can move at a super speed for a beat of her heart, before returning to the point she started moving from. She comes into contact with S.H.I.E.L.D. when they investigate her for stealing weapons from the corrupt members of the local police. She grows close to Mack, who nicknames her "Yo-Yo", and eventually agrees to join the Secret Warriors. After the signing of the Sokovia Accords, Rodriguez returns to her life with occasional monitoring by S.H.I.E.L.D.

By February 2016, Cordova-Buckley was cast as "Yo-Yo" Rodriguez, based on the comic Secret Warrior of the same name. Cordova-Buckley learned of the role after she had been cast in the series, and subsequently researched the comics for inspiration. She described the character, as she is initially introduced in the series, as a freedom fighter who "in a lot of ways she wants to help her people in Colombia and she wants to do good with her powers and she makes sure that she’s very adamant on how she goes about things." She also noted the rarity of the character's spirituality, saying that she "has this whole spiritual connection to her powers which is rare to ever see in a super hero movie...She wants to use [her powers] as what she calls a blessing and a gift from God to help others, so it’s a very unique approach to it all". When first portraying the character, Cordova-Buckley smiled whenever Rodriguez was about to use her abilities, to show an adrenaline rush and the feeling of having such power. After positive fan responses to this, the actress morphed this trait into a more mischievous personality for the character.

J.T. James / Hellfire

J.T. James (portrayed by Axle Whitehead) is an Inhuman who was refused the right of Terrigenesis by Jiaying and banished from Afterlife. Johnson subjects James to the transformation while under the influence of Hive, giving James the ability to imbue objects with fire. He is then taken under Hive's influence himself, and chooses the codename Hellfire. After Hive is destroyed, James suffers terrible withdrawal symptoms and comes to hate being an Inhuman as a result. He betrays his kind to the Watchdogs, helping them track and kill other Inhumans, with the promise that they would kill him when they are done.

Whitehead first guest starred as James in "Paradise Lost", introduced as someone from Lincoln's past, with Whitehead and Mitchell having previously starred together on Home and Away. With the character recurring through the rest of the third season, he was revealed to be an adaptation of the comic Secret Warrior character Hellfire. Executive producer Tancharoen felt it was "a no-brainer" to include Hellfire in the series, despite him not being Inhuman in the comics. Whedon expanded, saying, "We liked his attitude. He’s a tell-it-like-it-is guy. He’s a little bit of a prick. He does not care if he’s liked, and that’s fun to write." The producers were also able to find a way to incorporate Hellfire's signature fire chain into the series. In the fourth season, it is revealed that his full name is J.T. James.

Anderson

Anderson (portrayed by Alexander Wraith) is a S.H.I.E.L.D. agent and assistant to Coulson.

Piper

Piper (portrayed by Briana Venskus) is a S.H.I.E.L.D. agent and member of May's strike team.

Aida

Aida (portrayed by Mallory Jansen) is a Life Model Decoy, an android body based on Radcliffe's former lover and partner Agnes Kitsworth (also portrayed by Jansen) into which he transferred his artificial intelligence AIDA (voiced by Amanda Rea). After the Darkhold shows Radcliffe the secret to eternal life, Radcliffe programs Aida to go rogue in an attempt to steal the book from S.H.I.E.L.D. She is ultimately destroyed by S.H.I.E.L.D., and Radcliffe builds a new model of the android.

The artificial intelligence AIDA is briefly voiced by Amanda Rea in the third-season finale. By June 2016, casting was underway for a "very attractive" actress to portray the robot in a recurring role for the fourth season. The character was described as moving around "quite naturally", but speaking "a bit formally" like Iron Man's J.A.R.V.I.S. A.I. in the MCU films. In August, Jansen was cast in the role; she also portrays Agnes Kitsworth in "BOOM", for which she uses her native Australian accent.

Aida's costume was custom made, and inspired by the works of Alexander McQueen. Foley wanted it to be simple to "not take away from the character at all", but also "sort of a 'Where did this outfit come from?' kind of a feeling so that it's specifically hers. It just adds to the mystery of who she is." Jansen described "Aida 2.0" as being programmed to be more ruthless, with the character's costume a darker shade of gray than that worn by the original Aida to reflect these changes.

Robbie Reyes / Ghost Rider

Roberto "Robbie" Reyes (portrayed by Gabriel Luna) is a mechanic who, alongside his brother Gabe, was attacked by gang members who were hired to kill their uncle Eli Morrow. Gabe was paralyzed and Robbie was killed, but his life was saved when a Ghost Rider riding a motorcycle gave Robbie his power, creating a new Ghost Rider. Robbie lives to protect his Gabe, and at night he seeks out "vengeance" by hunting the guilty and murdering them. His actions bring him into contact with the vigilante Quake and the agents of S.H.I.E.L.D.

Advertisements for Agents of S.H.I.E.L.D. ahead of the 2016 San Diego Comic-Con International featuring a flaming chain lead to speculation that the character of Ghost Rider would be joining the series during the season, though it was noted that the image could indicate an increased role for Hellfire after his introduction in the third season. When casting for a Latino character matching the description of Marvel Comics' Robbie Reyes, was revealed to be underway for the series, further speculation pointed to the inclusion of Ghost Rider, a mantle that Reyes took over in the comics. At the series' Comic-Con panel, this speculation was confirmed, and Luna was announced to be cast in the role. On being cast, Luna felt it was "too good to be true" that Reyes "was a character who looked like me, acted like me, and had this amazing family dynamic with his brother".

Reyes was chosen as the Ghost Rider for the series, over other versions of the character, since his is the newest version from the comics, and the executive producers thought "it would be interesting to bring in someone with [his] background into our dynamic". Regarding if the character would be possessed by a Satanic serial killer, as in the comics, or by the more traditional Spirit of Vengeance, Tancharoen said, "We’re staying true to his circumstance. But as always with any property that we use, we’re taking our liberties with it," with Whedon adding that they would be "pulling a little bit from different versions of the Ghost Rider" with "a little mixing and matching". Luna said that due to the character's recent introduction in the comics, "a lot of the show is going to be expanding the Ghost Rider canon"; however Luna read all 12 issues of the All-New Ghost Rider series that introduced Reyes for preparation. The character drives a 1969 Dodge Charger in the show, the "Hellcharger" of the comics which Luna nicknamed Lucy, for Lucifer. The production had a hero car and a double for stunts, while the visual effects team used a CG double when needed. Eric Norris serves as Luna's stunt driver, with Morgan Benoit, a frequent collaborator with Luna, as his stunt double.

The character's signature jacket and flaming head were designed by Marvel Television creative director Joshua Shaw, based on Felipe Smith's design from the comics. The skull design includes exhaust-type jets of flames coming from the temples to mimic the effects on his car. For the CG skull, Luna wore tracking markers on his face to provide performance-reference for these sequences, especially for the animation of Ghost Rider's coal-like eyes. Luna also wears a hood fitted with flickering lights, to create the effect of fire lighting up his costume and surfaces around him. The lights can be adjusted to match different temperature fire for different situations. Whedon noted that the series depicts Reyes' flaming head "exactly as much as we can afford", adding, "We’re hoping that the character has not just a flaming skull but some real heart to him, and some depth." Foley paired the character's jacket with jeans and Vans to keep Reyes "grounded in the reality of where he was brought up in Los Angeles". Foley also worked with Kolpack to ensure that the costume would not interfere with the visual effects. Since a skeleton does not have a voice box, the Ghost Rider does not speak in the series.

In August 2016, Marvel Television head Jeph Loeb said that the character "could venture into other sections of the Marvel Cinematic Universe", depending on the audience's response to their take on him, saying, "if we can tell that story in a compelling way, then the thing to do is to then have people want more. And if they want more, the networks say, oh, we want more." On this, Luna noted that he "signed on the line to do all the work necessary ... that's extremely exciting." That October, Luna said that there had been "rumblings" about a spin-off for the character, but reiterated that it would depend on audience response.

Gabe Reyes

Gabriel "Gabe" Reyes (portrayed by Lorenzo James Henrie) is Robbie's younger brother, who was paralyzed in the accident that led to Robbie becoming the Ghost Rider.

Casting for a Latino character matching the description of Gabe Reyes, was revealed to be underway for the series at the same time as it was for Robbie. Robbie Reyes was confirmed for the series in September 2016, and Henrie was revealed to be portraying Gabe later that month. The role was one of the first that Henrie auditioned for after he finished filming for Fear the Walking Dead, in which his character is killed off. At his audition, Henrie confirmed that he would be able to dedicate his time to Agents of S.H.I.E.L.D. without spoiling the events of Fear for the S.H.I.E.L.D. casting team, and was cast in the role the next day. His introduction as Gabe aired only weeks after his Fear the Walking Dead death aired.

Lucy Bauer

Lucy Bauer (portrayed by Lilli Birdsell) was a scientist working at Momentum Labs in a group including her husband Joseph and engineer Eli Morrow. They were experimenting with the mysterious Darkhold, the Book of Sins, until Morrow took steps to gain the book's power for himself, creating a machine that turned Lucy and her co-workers into ghost like beings. Lucy later attempts to force Morrow to restore her body, but his nephew Robbie Reyes destroys her first with the power of the Ghost Rider.

Jeffrey Mace / Patriot

Jeffrey Mace (portrayed by Jason O'Mara) is the new Director of S.H.I.E.L.D., who was appointed to try and restore the trust of the public following the public outlawing of Steve Rogers and several of the Avengers due to the Sokovia Accords. Originally thought by the public and other members of S.H.I.E.L.D. to be an Inhuman with super-strength and invulnerability, Mace instead received his abilities from the U.S. government's Project Patriot, which used a super-serum derived from Zabo's formula. Mace received the serum after being heralded for a heroic moment at a ceremony in Vienna, Austria following the signing of the Sokovia Accords. With S.H.I.E.L.D. in need of a new, enhanced director on the recommendation of outgoing director Coulson, Talbot and the U.S. government gave the job to Mace, who they could trust. After it was revealed that Mace's powers were a lie, Coulson decided that Mace should stay on as "the Patriot" and the face and political leader of S.H.I.E.L.D., while Coulson takes back command of S.H.I.E.L.D. operations.

A flash-forward at the end of the third-season finale revealed that Coulson would no longer be the director of S.H.I.E.L.D. in the fourth season. The showrunners intentionally avoided giving hints as to who the new director would be in the sequence. After speculation in the media about which previously introduced character could be taking on the role, it was revealed that the new leader would actually be a new character to the series portrayed by O'Mara, described as a character "whose Marvel roots go back to the 1940s". The character was always going to be new to the series, as the executive producers felt that replacing Coulson with someone he knows "wouldn’t [provide] as much tension to mine from". The character was revealed to be Mace and an Inhuman with super strength with his introduction in "Meet the New Boss". O'Mara, a big Marvel fan as a child who has worked a lot with ABC, found out that Marvel was "really seriously" interested in him for the part in the same call that his agent told him that his A&E pilot The Infamous was not getting picked up to series. Within 24 hours, O'Mara had talked to Loeb, watched some of the third season of Agents of S.H.I.E.L.D., and accepted an offer to join the season without reading a script for it. He described the character as "high status", saying that "he comes in and he's the boss, telling the other characters orders. Here I come in after [the other actors] been doing this for four years and I'm telling them what to do. It's a little awkward".

Ellen Nadeer

Ellen Nadeer (portrayed by Parminder Nagra) is a senator and leader of the Humans First movement, who hates Inhumans after her mother's death during an alien invasion. Nadeer allies herself with the Watchdogs, but when high-ranking Watchdog Tucker Shockley tests Nadeer's humanity with a Terrigen crystal, it reveals his own explosive Inhuman abilities; Nadeer dies in the ensuing explosion.

Eli Morrow

Elias "Eli" Morrow (portrayed by José Zúñiga) is the uncle of Robbie and Gabe Reyes, and engineer who helped raise his nephews. After his coworkers at Momentum Energy labs began experimenting with the Darkhold, Morrow came to crave its power for himself. He put Joseph Bauer into a coma trying to find the book, and ultimately turned the rest of his coworkers into ghost-like beings. S.H.I.E.L.D. breaks him out of prison believing him to be a victim, but he uses the Darkhold to create a machine that gives him the power to create matter.

The comics version of Eli Morrow is a Satanist who, after dying, possesses his nephew Robbie and turns him into the Ghost Rider. In August 2016, Whedon cautioned that the series would not necessarily be directly adapting the comics' storyline, saying, "We can’t say much about what we’re going to do with [Robbie Reyes’] origin, but we are doing our own spin on it. We don’t want people who have read the comics to know exactly what’s coming." In October, Morrow was confirmed to be appearing in the series, with Zúñiga cast. He is changed for the series by introducing him as an apparently innocent man, and then revealing him to be as power hungry as his fellow scientists experimenting on the Darkhold. The abilities he gains from his experiments have been compared to those of the comic character Molecule Man.

Anton Ivanov / The Superior

Anton Ivanov (portrayed by Zach McGowan) is a reclusive Russian industrialist known as "The Superior", who champions traditional values and old-fashioned hardware over modern technology and extraterrestrial entities. He believes that Coulson is the cause of Earth's alien problems, and works with the Watchdogs, Senator Nadeer, and Holden Radcliffe to fight S.H.I.E.L.D. After being crippled by Daisy Johnson, Aida decapitates Ivanov, and creates an android body for his mind to control.

Guest characters

The following is a supplementary list of guest stars that appear in lesser roles, make significant cameo appearances or who receive co-starring credit over multiple appearances. The characters are listed by the MCU media or season in which they first appeared.