Mystique

Mystique is a mutant and the leader of the Brotherhood of Mutants formerly under the command of Magneto. The two betrayed each other. She later became a part of the Horsemen of Apocalypse.

Biography
Mystique had a son, who would become Nightcrawler. However, he had an altered appearance from birth and she was revealed as a mutant. Villagers chased her and she abandoned the child.

She and Destiny found a girl named Rogue and they became her foster parents. The two manipulated her so that she would eventually be an ally.

She met Magneto at an unknown time and became his right-hand woman. She went to Bayville where the Xavier Mansion was located and became the principle of Bayville High School, where those who lived at Xavier's went to school, under the name Raven Darkholme.

She started the Brotherhood of Mutants and recruited Toad, Avalanche, and Blob. Magneto had her get Quicksilver, who was actually his son.

When Magneto revealed his ultimate plan for mutantkind with Asteroid M, he had her fight Storm to prove herself. However, she lost and then guided the other Brotherhood and X-Men members left behind to the secret base. She went into the chamber with the Crimson Gem of Cyttorak where her powers were greatly increased.

With her reputation in ruins, Mystique took on a teenage girl form and called herself Risty Wilde to befriend Rogue. She used Rogue to get inside the mansion then blew it up.

She was later manipulated by Mesmero to release the ancient mutant Apocalypse. However, releasing him turned her to stone.

Her son Nightcralwer tried to help her but Rogue pushed the statue off a cliff apparently killing her.

However, she had really been altered into becoming a Horseman of Apocalypse. Her powers were radically altered. Though Apocalypse was defeated and she was released.

Powers and Abilities
Raven has the ability to change her body into any other person, and several kinds of animals. However, she cannot mimic any powers, only the physical appearance.

Her powers were increased on Asteroid M, enabling her to change her scent to match the forms she took and her own body became scentless. Additionally the enhancement made her immune to telepathyic probing and mind control.

When under the command of Apocalypse, her powers vastly increased. She could transform into multiple beings at once, a liquid state, and even regenerate lost limbs. However, these changes were reversed when she was released.

Due to the nature of her powers, she is in fact always naked and the clothes are simply extensions of her body.

Personality
Mystique is a ruthless and feared mutant, and a unscrupulous manipulator.