Dark Mother (Fiona Knoblach) is a fictional character, a mutant appearing in American comic books published by Marvel Comics. Her first appearance was in Cable #88.
Leader of the shadowy organization known as the Dark Sisterhood, the Dark Mother ruled with an iron hand, and was willing to do anything to further her aims, no matter how depraved.
The Dark Sisterhood began long ago when women born with unusual powers began banding together for protection. Called witches, they adopted the name of the Dark Sisterhood originally in defiance of their persecutors. They sought power to save themselves from death and torture, but over time their goals became twisted. They sought not just to be equal, but to rule; to replace a corrupt system with their own. Today, the Sisterhood use their mutant psychic abilities to manipulate crucial figures in every level of society - from huge crime cartels to renegade police officers, corporate CEO's, and even heads of state. All to further their goal of global domination.
A powerful mutant psychic and telekinetic herself, the Dark Mother, using the alias Finality, approached Cable's mentor Blaquesmith seeking help. Believing the Sisterhood's aims coincided with that of the Askani, Blaquesmith aided them by arming them with psimitars.
When Cable became aware of the group's presence, the Dark Mother ordered him and any who stood with him killed. A band of twenty members of the Dark Sisterhood attacked Cable's Hell's Kitchen safehouse, but he defeated them and destroyed the base.
Cable then set about stopping the Dark Sisterhood from installing one of their own as the next President of the United States. During the final battle with Finality, Cable regressed her mind - and the minds of the remainder of the Dark Sisterhood - to that of an infant.
She claimed to both Nathan and Rachel Grey-Summers to be the direct ancestress of the Grey family ( i.e. their maternal great +-grandmother ), but this was later denied by the pair after they had defeated her. It was later confirmed by Robert Weinberg, the writer of Cable at the time of the Dark Sisterhood storyline, that he had indeed originally intended Finality, as well as her brother Clarity, to be the maternal ancestress of the Grey family, but he was forced to cancel the story at the last minute. This story ended ambiguously however, without absolutely confirming or denying the Finality's shocking revelations to her alleged descendants, and so this particular plotline remains open-ended as of the current moment.
Later, Mister Sinister had a plan for dealing with M-Day the day a distraught Scarlet Witch used her reality-altering power in an almost-completely successful attempt to turn all mutants into normal humans. Keeping the X-Men from finding out was part of that plan, so the Marauders and the Acolytes, attempted to kill known psychics, precognitives, and persons with a direct knowledge of the future, as well as steal those volumes of the late Destiny's Diaries that were in Shadowcat's possession. Blockbuster, Prism, and Riptide were sent to kill Dark Mother. From the information that Emma Frost took from the Marauders' minds in battle, they apparently succeeded.