I'll explain my teams logic (this one was semi-thought of)
the thing is based around Cable coming back from the future and needing to do something that right now (in our present) seems wrong. He goes to Magneto and explain what needs to be done and Magneto decides to help him out. The rest of the team are individual that in my opinion, border between good and evil. They might not know at the beginning what Cable and Magneto's plans are, but they trust Magneto.
Pandora is a DC character that is cursed and forced to walk the world for eternity to experience the pain she wrought by releasing the spirits of evil upon man. She's part of the team because Magneto convinced her he knows how to reverse the curse.
Wesley Gibson is the killer in Wanted Agent Zero is maverick after getting the Weapon X treatment