I don't believe that. She still thinks she is an angel, in the game she clearly states she took over hell only, and thinks highly of Angels and heaven. She considers her triumph over hell was largely part of she being an angel and having a purpose. Is actually kind of sad as it seems she is doing her research on sin to make up for her action and to prove she is still a good Angel. Also I don't think she is evil as the ending shows she is still Azazel deep down. My crazy Headcanon: at some point she tried to go back to heaven and was cast out because she was a from now and this sent her to a downward spiral.

Also on her campaign to conquer Hell she lost both of her arms, she has robotic ones now. She has gone through a lot