In Dark Phoenix, the last entry in Fox's X-Men saga, Jean Grey becomes the most powerful entity in the galaxy. However, that kind of power attracts unwanted attention. For Jean, that came in the form of Vuk, the leader of the D'Bari people. After her planet was destroyed by the Phoenix Force, Vuk sought the means to control it -- even if that meant controlling Jean herself. According to Jessica Chastain, her alien empress ended up empowering the beleaguered X-Man along the way.

"We wanted all of these fantastical things that are happening to Jean to be grounded in reality in a way," Jean actor Sophie Turner explained to CBR. "So we studied schizophrenia and dissociative identity disorder and immediately, just researching it, you can just kind of feel a person's frustration and anger that they can't control this thing within them. So, when Jean lets out this Phoenix Force, it manifests itself in very destructive ways and a lot of that is because of the frustration of not being able to control this thing and not being allowed express it as well, for fear that it might hurt someone, so that's where her rage comes from."

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"What I also like about the film is it says that rage is okay, and I think a lot of women don't think it is or, you know, have been led to believe that they need to be quiet and polite and just play by the rules," Chastain added. "I know my character comes in and is trying to manipulate Jean for her own advantage, but -- in doing so -- she really empowers her and lets her know that, 'Stop following the rules of this man who's using your power for himself. It's time for you to make your own rules.' I think that's an important part of the female rage that you're bringing up."

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Asked how they developed this relationship for the film, Turner said, "It's interesting! People have asked us how we established the dynamic, but we didn't really! It's all kind of in the script."

"Also, too, when you're working with someone who's a great actor like Soph is, they do a lot of their research at home. A lot of the work happens before you ever arrive, so then -- when you arrive on set and you're about to do your scene -- there's so much already loaded in the performance, and that you can just really be present in the moment and react to each other, because I've come with my history, my backstory, my preparation. Now she's come with hers," Chastain shared.

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"It was so cool being in the first scene that I did with Jess, and all of a sudden seeing this take that she had on the character and I was mesmerized by it," Turner recalled. "That's just reacting, but it was so perfect for their relationship. I was just like, 'Who are you?!'"

Turner also addressed the idea of "likeable" female characters with flaws. "Every person, every human, every woman has flaws. It's just natural, and so I just didn't even think of it when I read this script because it's normal. That's what a woman is," she said. "That's what being human is. You know, it was definitely refreshing, because it's kind of a needle in a haystack to find a script where a woman is written accurately. So that's something that I just loved, but you know, it's just accurate. It's the way humanity is."

Directed and written by Simon Kinberg, Dark Phoenix stars James McAvoy, Michael Fassbender, Jennifer Lawrence, Nicholas Holt, Sophie Turner, Tye Sheridan, Alexandra Shipp, Kodi Smit-McPhee, Evan Peters and Jessica Chastain. The film is out in theaters now.