After the ending of 2011's X-Men: First Class, most assumed that Jennifer Lawrence's Mystique will be closely aligned with Michael Fassbender's Magneto in X-Men: Days of Future Past. However, the actress revealed that she actually starts out on her own, where she has her first kill.
"We find Raven, she's split off from Eric and Charles, and she's kind of her own agent. She has one mission of trying to assassinate somebody and it will be her first kill, basically. Because we've seen her in the future, and what she becomes, this is kind of a turning point for her."
It isn't known who this first victim may be quite yet, but it certainly seems like an integral part of the story.