Information on which character is unavailable, but a strong possibility is Lilandra, an alien empress who, in the comics, forms a strong relationship with Professor X. She and the Shi’ar Empire are pivotal to the Phoenix storyline.
Dark Phoenix was also the antagonist of 2006’s X-MEN: THE LAST STAND.
Another possibility is Selene, a mutant who has ties to the Hellfire Club and abilities that can play a role in manipulating Jean to the dark side.
There has been no confirmation if either actress has actually been contacted or offered the part. But with filming starting in the next few weeks, we’ll surely find out sooner rather than later.
Both have worked with Xavier actor James McAvoy in the past; Jolie on “Wanted” and Chastain on “The Disappearance of Eleanor Rigby.”
Personally I think Jolie would do amazing in the as Lilandra. She has that regal quality.
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