Mystique, book 4: Quiet
Sean McKeever2005

Raven Darkholme aka Mystique has cracked. We must say that it's not every day you discover a pharmaceutical lab uses mutants as guinea pigs, and even conducted experiments on clones of yourself.
This abomination destroy the vow of conduct of the mutant shapeshifter, who had promised to Xavier and Shortpack she did not kill during her missions.
Following its deviations Shortpack told Xavier that he no longer wants to work with Raven. Mystique will it switch on the side of the mysterious Quiet Man, who asked her to assassinate the founder of the X-Men?
(Collects MYSTIQUE #19-24)