Shape shifting
The shape-shifting blue woman who frequently appears in X-men comics, cartoons, and movies is Mystique.
No.
Mystique from X-men: her real name is Raven
Yes, she does talk occasionally
There are several shapeshifters in X-Men, but perhaps the best known is Mystique.
you can't
Mystique is primarily portrayed by Jennifer Lawrence in the recent X-Men film series, starting with "X-Men: First Class" in 2011. Prior to Lawrence, the character was played by Rebecca Romijn in the original X-Men trilogy. Mystique is known for her shape-shifting abilities and complex character arc throughout the franchise.
Because if you watched the movies then you would see that First Class was set before the X-trilogy, when Professor X, Magneto and Mystique were friends. At the end of First Class, Magneto splits from Professor X and Mystique joins him. Magneto and Professor X are enemies, so Mystique would be an enemy of Professor X since she is in alliance with Magneto.
Mystiqe was already in the comics
Rebecca Romijn didn't reprise her role as Mystique in the last two X-Men movies because she was too old to play the teenaged Mystique. That's why it went to Jennifer Lawrence.
Because in X-Men first class she is on Professor X's side but in the X-Men movies she is with Magneto and has to do whatever he tells her to do
Yes, she plays Mystique / Raven Darkholme.