Outside of his work within these promotions, Cosme has represented Puerto Rico as a member of Team Rest of the World in the 2015 Lucha Libre World Cup and as the captain of Team International in the 2013 World Cup of Wrestling.
Cosme began wrestling training in 1996, when he was instructed by a former wrestler. During this time he was enrolled in the Interamerican University of Puerto Rico located in Bayamón, his major concentration was in computer technology, after completing two years of study, he decided to begin wrestling as a profession after meeting Victor Quiñones in the gym. In 1997, after working in the independent circuit he moved to Mexico and performed there, and became involved in a project to develop Hispanic talent organized by the World Wrestling Federation.
Cosme subsequently debuted in the International Wrestling Association (IWA) in 1999. He was given the gimmick of "El Patriota" Ricky Banderas, a name that, according to Cosme, was created by fusing the artistic names of Latin musician Ricky Martín and actor Antonio Banderas. He debuted in Extreme Championship Wrestling on that year, where he worked in a televised match. Following a period of teaming with Los Boricuas, his character was teamed with Germán Figueroa who wrestled as Gran Apolo, and formed a tag team dubbed La Nueva Generacion, which won the IWA Tag Team Championship three times. On August 21, 2000, in a show in Levittown, Puerto Rico, Cosme's character turned on Gran Apolo. Following this, he joined the company's dominant heel stable, Los Intocables, along with Miguel Pérez and Jesús Castillo. After the stable's dissolution, he was involved in another stable named Starr Corporation, where after Cosme's insistence his character became darker and was renamed "El Mesías" Ricky Banderas. Following this, he was teamed up with Shane Sewell in a stable known as Los Hermanos en Dolor. In 2001, Cosme performed in a tryout match for the World Wrestling Federation and in a pay per view event on Frontier Martial-Arts Wrestling. He won the IWA heavyweight title for a third time on June 15, 2002, and remained champion until Ray González debuted with the company as "Rey Fénix", in a match that he describes as the best match he had wrestled at the moment.
Cosme's gimmick underwent another change when it joined then-dominant heel stable "La Compania" led by Savio Vega (Juan Rivera). This was followed by his fourth title run after he defeated Gran Apolo on January 6, 2003. He was booked as a heel until October 9, 2003, when Vega's group turned on him. Following this, he feuded with Christopher Kindred under his "Slash Venom" gimmick, which peaked when Vampiro (Ian Richard Hodgkinson) was brought by the company to form a stable which feuded with Gran Apolo and Venom. In 2004, he feuded with Hangman Hughes (Mike Hughes), Kasey James (Kurt Sellers), El Diamante (Julio César Cruz), and Bison. In 2005, he turned heel again, this time leading a stable known as La Cruz del Diablo which feuded with other groups led by Savio Vega and Ray Gonzalez. Following an angle where he feuded over a number one contender spot, Cosme departed from the company and signed a contract to wrestle in Mexico. Subsequently, he continued making sporadic appearances for the company, including a brief stay in 2007. On July 19, 2009, Cosme was booked to defeat Dennis Rivera in the promotion's tenth anniversary event.
Following the culmination of his contract with the International Wrestling Association, Cosme signed a contract with Lucha Libre AAA Worldwide (AAA). He debuted on March 12, 2006, as "Muerte Cibernética" a rudo (villainous) enforcer supposedly brought to the company by Cibernético to feud with "La Parka". This gimmick consisted of Cosme wearing a traditional Mexican wrestling mask, often a modified version of the one used by La Parka. This character was placed in a feud with La Parka, which lasted several months. This angle came to a conclusion at Triplemania XIV, where Cosme's character was booked to lose a Mask vs. Mask match.
Following a legitimate injury suffered by Cibernético, Cosme's gimmick was slightly changed, launching into an angle where he pursued the leadership of Cibernético's stable, which then went by the name of La Secta Cibernetica. The character was booked to be the leader of the stable after supposedly convincing several members of the group to join him changing the name of the group to La Secta Diabólica. The events of the angle were used to hype an eventual feud between López and Cosme's characters that took place in December 2006. In the angle, Cosme won the first encounter between the two with help of his stable. The angle culminated in a Casket match between the two characters. Cibernético was booked to win the match and subsequently "kill" his opponent by throwing him into an active volcano. This was used to explain Cosme's absence when he departed from the company to wrestle in the International Wrestling Association. During this time he also wrestled for Panama Wrestling Crew in Panama and in Ecuador.
Following a month of performing in Puerto Rico, Cosme returned to AAA in an annual event entitled Rey de Reyes under a new gimmick, changing his name to El Mesías. From then on, he started to get a bigger push as a main event heel, feuding with Cibernético and his stable "Los Hell Brothers". During the feud, Cosme was both leader of La Secta del Mesías and member of La Legión Extranjera. Later, Cosme took both the IWC heavyweight championship from Cibernético and the GPCW SUPER-X Monster Title from La Parka in the preliminary rounds of the AAA Mega Championship tournament. As Mesías, he became the first wrestler to win the AAA Mega Championship in AAA's pay-per-view event Verano de Escandalo after defeating Chessman(Kevin Citlali Zamora) by disqualification. On November 29, 2007, he successfully defended the company's championship in a triple threat match at a pay-per-view titled Guerra de Titanes. In March 2008, he returned to AAA after several months of inactivity. On March 16, 2008, Cosme dropped the championship to Cibernético. He was subsecuently involved in an angle with Vampiro, leding to a match at Triplemania XVI, which concluded as a time-limit draw. On October 24, 2008, Cosme won the Copa Antonio Peña, defeating six other wrestlers in the process. Joaquín Roldán, was responsible for presenting the relevant trophy. On December 6, 2008, at Guerra de Titanes, Cosme won the AAA Heavyweight Championship for a second time, defeating El Zorro (Jesús Martínez). He also made a full técnico (fan favorite) turn, asking the fans for forgiveness for what he's done while in AAA. On March 15, 2009 at the Rey de Reyes (2009) After successfully defending the AAA Mega Championship against Chessman, Dr. Wagner, Jr. challenged him directly after the match. On June 13, 2009, he was booked to lose the title to Wagner at Triplemania XVII.
The feud continued for several months, until he regained the title on December 11, 2009, at the main event of Guerra de Titanes. Cosme's third reign as AAA Mega Champion ended on March 12, 2010, at the 2010 Rey de Reyes event. He was not booked to lose, but Electroshock (Edgar Luna Pozos) submitted Mr. Anderson (Ken Anderson), the third wrestler in the match, to win the championship. Afterwards, El Mesías began feuding with invaders from Los Perros del Mal, the group's leader El Hijo del Perro Aguayo in particular. On August 14 at Verano de Escandalo Aguayo, Damián 666 and L.A. Park defeated El Mesías, Cibernético and La Parka in a six-man tag team match, when Aguayo pinned Mesías after hitting him with a chair. On October 1 at Héroes Inmortales IV El Mesías gained a measure of revenge on Aguayo by defeating him in a singles match. On November 1 El Mesías entered the 2010 Lucha Libre Premier tournament. The first two rounds of the tournament were wrestled in a parejas increibles format, with El Mesías teaming with Electroshock. The two would defeat the teams of Extreme Tiger and L.A. Park and Cibérnetico and Hernandez to make it to the semifinal four–way match, where El Mesías and El Zorro, defeated Electroshock and Dr. Wagner, Jr. to advance to the finals. On November 28 El Mesías defeated El Zorro in the finals of the tournament to win the 2010 Lucha Libre Premier. Afterwards Mesías entered a feud with La Sociedad member L.A. Park, who defeated him on December 5 at Guerra de Titanes, after using a chair on him. On March 18, 2011, at Rey de Reyes, El Mesías and Park were both eliminated from the finals of the 2011 Rey de Reyes tournament, after brawling to a double countout. On May 18, El Mesías challenged, and Park accepted, for the two to end their feud at Triplemanía XIX in a Mask vs. Hair match. On June 18 at TripleManía XIX, Park defeated El Mesías, forcing him to have his head shaved. El Mesías returned to AAA a month later at Verano de Escándalo, saving Dr. Wagner, Jr. from La Sociedad. On October 9 at Héroes Inmortales, El Mesías wrestled TNA performer Sting to a no contest in what was billed as a "dream match" by AAA, following interference from La Sociedad. The match had been put together by AAA Mega Champion Jeff Jarrett in an attempt to stop El Mesías from chasing his title. On December 16 at Guerra de Titanes, El Mesías defeated TNA performers A.J. Styles and Rob Terry in back-to-back matches to become the number one contender to Jarrett's title. On March 18, 2012, at Rey de Reyes, El Mesías defeated Jeff Jarrett to win the AAA Mega Championship for the fourth time. On April 23, El Mesías underwent surgery on his arm; as a result, he was sidelined from in-ring action for three months. In storyline, El Hijo del Perro Aguayo was credited with causing the injury. El Mesías returned on July 13, attacking Aguayo and his Perros del Mal stable. On August 5 at Triplemanía XX, El Mesías successfully defended the AAA Mega Championship against Aguayo. He then went on to lose the title to El Texano, Jr. on December 2 at Guerra de Titanes. On March 17, 2013, El Mesías defeated Canek and L.A. Park in the finals to win the 2013 Rey de Reyes tournament. In October, El Mesías came together with two former rivals, Cibernético and El Hijo del Perro Aguayo, to battle the Secta stable, after its members had turned on Cibernético. The partnership was ended on December 8 at Guerra de Titanes, when Aguayo turned rudo, leading to the reformation of La Sociedad. On August 17, 2014, at Triplemanía XXII, El Mesías won fellow técnico Electroshock's hair in a six-way steel cage Lucha de Apuestas.
On March 6, 2015, El Mesías turned on Blue Demon Jr. and La Parka, completing his return to the rudo side. Shortly afterwards, he joined La Sociedad.
Cosme participated as Banderas in the Wrestling Society X television series (taped in Los Angeles, California), with the gimmick of a disgruntled and kayfabe disfigured man pursuing a feud with Vampiro. The booking of the feud commenced after Banderas threw a fireball at Vampiro's face, which resulted in MTV pulling the episode from its original airdate, with concerns that viewers would try it at home.
The reason behind the pursuit was explained in the following episode in a promo, where he claimed that Vampiro rigged a casket with explosives during a match, with the explosion resulting in the damage done to his face. On the eighth episode (which was taped on November 15, 2006) of the series, Banderas won the WSX Championship in his debut match for the promotion. Beforehand, he was involved in a series of brawls with Youth Suicide (Andre Verdun), as well as an allusion to a partnership with 6-Pac (Sean Waltman).
As noted on the "TNA Mobile" service, Cosme signed a contract with Total Nonstop Action Wrestling (TNA). Cosme was billed as James Mitchell's kayfabe son and thus Abyss' brother. Beginning on July 1, 2007, vignettes began to air for this "monster-like" character. His name was eventually billed as Judas Mesias. At No Surrender, he pulled Abyss under the ring by cutting a hole through it with a knife and pulling him underneath. On the September 13, 2007 episode of Impact!, during a submission match between Abyss and Kurt Angle in the Six Sides of Steel, Mesias made his official debut, climbing up from underneath the ring and subsequently attacking Abyss. On the September 20 episode of Impact!, Mesias defeated Eric Young in his debut match in TNA.
On September 21, 2007, it was reported that Cosme was suffering from sciatica and that the condition's treatment required several weeks of rest, followed by physical therapy to recover. This injury was the result of a fall from a ladder during a championship match at AAA's Verano de Escandalo pay-per-view, which also knocked him out.
Mesias returned on the December 13, 2007, episode of Impact! where he attacked Abyss by strangling him with a piece of barbed wire, which he also used to cut his forehead open. He then repeatedly hit Abyss in the head with a chair. He finished his assault by delivering his finisher, Straight to Hell to Abyss on the same chair. In his TNA pay-per-view debut, Mesias defeated Abyss at Final Resolution after hitting Abyss with his finisher onto a barbed wire steel chair. This feud continued at Against All Odds, organized on February 10, 2008. In this event he competed in a stipulation match called "Barbed Wire Massacre", where the ring was surrounded by barbed wire, which Abyss won by using his finisher, the Black Hole Slam. In March, Cosme was released from his contract with the company.
On March 18, 2013, Cosme made a one night return to TNA to take part in the tapings of the TNA World Cup of Wrestling One Night Only pay-per-view. Working as Messias, he represented Team International in a singles match, where he was defeated by Team United States' James Storm. At the tapings of the following day's Hardcore Justice 2 pay-per-view, Mesias, once again managed by James Mitchell, was defeated by Joseph Park in a Monster's Ball match.
An agreement between Cosme and the World Wrestling Council was first rumored on November 26, 2009. The promotion made the official announcement two days later, including highlights of his career in a compilation video displayed during a special event titled Crossfire. His debut was scheduled for January 16, 2010, being booked as Ricky Banderas in a contest against Carly Colón. Ray González was subsequently included, winning a three-way-contest where the WWC's first winner of the "Wrestler of the Decade Cup" was to be decided. The following week, both were booked in a rematch, with Banderas winning the cup. On July 11, 2010, Banderas was booked to act as special referee at Aniversario 2010, but was subsequently included in a stipulation match against Colón. His character made a heel turn in this event, attacking both Colón and Hugo Savinovich. On January 8, 2011, Banderas defeated Colón, with help from an interfering Shane Sewell, to win the WWC Universal Heavyweight Championship for the first time. Cosme was stripped of the title upon returning to the IWA, headlining an angle that revisited the promotion's first decade. His sole match took place on April 2, 2011, where he defeated González, who had since returned to his masked "Rey Fénix" persona, in the main event of the evening. Following this match Cosme's involvement in the IWA concluded, remaining inactive in Puerto Rico until January 7, 2012, when he reappeared in WWC programming asking for an opportunity to challenge Carly Colón for the Universal Heavyweight Championship. The challenge was accepted and took place at Euphoria 2012, but was inconclusive after Savio Vega interrupted by distrating Colón, which drained what was left of the preestablished time.
In September 2014, Cosme began working for Lucha Underground under a mask and the ring name Mil Muertes. In storyline, Muertes' real name was Pasqual Mendoza, whose entire family died in an earthquake in Mexico City, when he was seven years old. He debuted on the episode, which aired on November 6, 2014, accompanied by Catrina as his valet. He was then involved in a major rivalry with Fénix (punctuated by Catrina's turning on him and aligning herself with Fénix), which concluded when Fénix defeated him in a "Grave Consequences" casket match that aired on March 18, 2015. After being "resurrected" by Catrina, Muertes returned and on April 19, 2015, at Ultima Lucha, Lucha Underground's season one finale, defeated Prince Puma to win the Lucha Underground Championship.
During the season two premiere on January 27, 2015, Muertes successfully defended the Lucha Underground Championship against Ivelisse despite spearing Catrina. On August 5, 2015 Muertes was defeated by Fénix for the Lucha Underground Championship. On Lucha Underground Monster Meets Monster Muertes fought Matanza Cueto for the Lucha Underground Championship to a No Contest. At Lucha Underground Graver Consequences Muertes was defeated by Matanza Cueto for the Lucha Underground Championship in a Graver Consequences Casket Match. At Ultima Lucha Dos part 2 Muertes defeated King Cuerno in a Death Match. On November 16, 2016 Muertes was lastly eliminated by Sexy Star in Aztec Warfare for the Lucha Underground Championship. At Lucha Underground Bulls Of Boyle Height Muertes was involved in a Battle of the Bulls Tournament Fatal Four Way Match with was won by The Mack. On a Lucha Underground Taping Muertes was defeated by Prince Puma in a Street Fight. On Lucha Underground Taping Muertes was involved in the Cueto Cup Second Round where he defeated Paul London. Muertes defeated Jeremiah Crane in the Third Round of the Cueto Cup but was defeated in Fourth Round by Pentagon Dark.Finishing movesMil MuertesFlatliner (Reverse STO, sometimes while jumping)Dagger in the Heart / The Reaper's Trident (Spear)As Ricky BanderasDouble leg slamFrog splashLa Patriota (Sharpshooter)As El Mesías / Judas MesiasJumping reverse STO (AAA) / Straight to Hell (TNA)Sharpshooter – AAASignature movesCradle piledriverFlowing DDTPowerbomb facebusterReverse figure-four leglockSamoan dropSuperplexManagersJames MitchellCatrinaEntrance themes"Carmina Burana" by Carl Orff"Seek & Destroy" by Metallica"Birth of Venus Illegitima" by Therion"Ave Vampire" by Dale Oliver (TNA)"Lux Æterna" by Kronos QuartetInternational Wrestling AssociationIWA World Heavyweight Championship (6 times)IWA Intercontinental Championship (3 times)IWA World Tag Team Championship (6 times) – with Gran Apolo (3), Miguel Perez, Jr., Huracan Castillo, Fidel Sierra, Pain (1) as Los Intocables, Glamour Boy Shane (1) and Cruzz (1)IWA Hardcore Championship (10 times)Lucha Libre AAA WorldwideAAA Mega Championship (4 times)AAA World Tag Team Championship (1 time) – with PaganoGPCW Super-X Monster Championship (1 time)IWC World Heavyweight Championship (1 time)Trident Championship (1 time)Copa Antonio Peña (2008)Lucha Libre Premier (2010)Rey de Reyes (2013)Lucha UndergroundLucha Underground Championship (1 time)Promociones EMWEMW World Heavyweight Championship (1 time, current)Pro Wrestling IllustratedPWI ranked him # 26 of the 500 best singles wrestlers in the PWI 500 in 2008 and 2015World Wrestling CouncilWWC Universal Heavyweight Championship (1 time)Copa Luchador de la Década (2010)Wrestling Society XWSX Championship (1 time)