Throughout most of her history, Mystique has been a supervillain, founding her own Brotherhood of Evil Mutants and assassinating several important people involved in mutant affairs. Mystique herself is a mutant, a shapeshifter whose natural appearance includes her blue skin and yellow eyes. At one point, she mentioned she is over 100 years old. Mystique is the mother of the villain Graydon Creed, the X-Men hero Night Crawler, and foster mother of the hero Rogue. She was forced to abandon Nightcrawler, but raised Rogue for a number of years and the two women have mixed feelings towards one another
Mystique is a mutant shapeshifter with the ability to psionically shift the formation of her biological cells at will to change her appearance and thereby assume the form of other humans. She can also alter her voice to duplicate exactly that of another person. Originally, it was clearly stated that Mystique's powers were limited to appearances only; she could not assume the powers of the people she morphed into or alter her body to adapt to different situations. In addition, she could not change her overall body mass when taking on the appearance of a person larger or smaller than she is. Her body is not limited to purely organic appearances. She has the ability to create the appearance of clothes out of her own body. Mystique was shown in at least one instance transforming a metallic part of her costume into a functioning blaster pistol. Whether this was a function of her powers or of the costume piece itself is unclear. She can transform part of her body into a separated, clear and hard substance that appears to be glass, as she does when she appears to be wearing glasses.
As a side effect of this power, her natural aging process has been suppressed (if not completely halted), as she has retained her youthful appearance despite being alive for over one hundred years.
This changed in 2001's X-Men Forever miniseries, in which Mystique was exposed to dangerous levels of radiation in order to save the life of Toad. The process morphed Mystique's appearance to match her more reptilian physique from the 2000's film trilogy, and boosted her powers so that she could now morph her body into taking certain desired physical traits depending on her situation at the time. Examples of this new ability include night vision, wings on her back, talons in her fingers, and natural body armor. She can even compress nearly two-dimensional like a sheet of paper to glide on air currents, similar to Mr Fantastic, which she uses to survive an explosion. She has moved her vital organs out of place in order to survive a gunshot to her torso. She has, once with strain, given herself two heads and four arms to facilitate a gun fight on two fronts, as well as shapeshifted into herself as a child.
Damage to her biological tissue is known to heal at a relatively fast rate and she can form a resistance to poisons upon contracting them. Recently she has stated that her body mass is not fixed and can change when she does. While she retained her advanced powers, she now appears in her old form without scales. Her powers grant her immunity to diseases, agelessness, and enhanced agility.
Mystique is a cunning strategist in terrorist and commando operations, and adept at martial arts and information technology. She has a talent for finding, stealing and understanding cutting edge weaponry. She is a talented actress. She has some natural resistance to telepathic intrusion and wears devices to prevent her mind from being read by telepathy.