"Because of the timing of when I came into the industry, I decided for me — my career could go away tomorrow, and I'll do something else, and I'll be okay. Because I was okay before I came into this career. For me, there's a lot that I have that isn't acting. I made a decision very early on to not work with people that I felt abused their positions, and didn't create a healthy environment for those around them," Chastain told The Daily Beast. "I actually chose to do X-Men because I'm working with Simon Kinberg, who's also a first-time filmmaker who I met on The Martian, and is an incredible writer and producer. He wrote this script — which I can't say much about, because it's X-Men — and there are many powerful female roles in this story that Simon is telling. And all of my dealings were with Simon and Hutch [Parker, another producer], who were on set."