The first-look feature on X-Men: Dark Phoenix has revealed a lot of plot and character details, but the most interesting insight is definitely who or what actress Jessica Chastain (Zero Dark Thirty) is playing in the film.
According to the EW article, Jessica Chastain's Dark Phoenix character is a definitely not on the side of the angels, described as, "an otherwordly shapeshifter who manipulates Phoenix for her own agenda. Chastain's villain is quiet but brutal."
In the actress's own words, her character is performing something akin to cosmic surgery: "...I keep thinking of the vet who tells you you need to put your dog down. There’s something very clinical about it."
These new insights should jump out at Marvel Comics fans, as they leave room for certain iconic characters to be the inspiration for Chastain's character:
In the comics, Mastermind (Jason Wyngarde) is a carnival mentalist who is actually a mutant with the ability to project illusions into the minds of others. His illusions are so strong, that even a person aware of the manipulation can't break free of it. Without artificial restraints, Mastermind's power can spread uncontrollably, sometimes affecting an entire town.
Obviously, there is a lot of difference between Jason Wyngarde on the comic book page, and Jessica Chastain in X-Men: Dark Phoenix. However, when you consider certain factors, there's merit to this possibility:
The X-Men movies have definitely taken liberties with their character adaptations in the past, so it wouldn't be too surprising if the Mastermind role in Dark Phoenix was streamlined to better fit the larger cosmic storyline.
Marvel Comics has an entire race of manipulative, shape-shifting aliens: The Skrulls. There conniving green aliens have been the subject of a lot of discussion the fast few years, regaridng how and where they can be used.
This past summer, The Skrulls were confirmed to be the villains of Marvel Studios' upcoming Captain Marvel movie, suggesting that Marvel Studios has worked out some kind of usage deal with Fox, who technically own the rights to the Skrulls. However, it was rumored just this fall that The Skrulls could appear in Dark Phoenix as well. We've seen Fox and Marvel share characters before, as Quicksilver appeared in both X-Men: Days of Future Past and Avengers: Age of Ultron within the same year. In that tradition, both Captain Marvel and X-Men: Dark Phoenix could have Skrulls.
Having Chastain be a Skrull operative or queen would check all the boxes of what her character is described as being. Shape-shifter, manipulator, trying to cleanse the Earth; it all sounds pretty Skrully, to us. There's also the fact that Wikipedia lists Chastain's character as being as, "Veranke: The Skrull Queen who seeks to capture and destroy the Dark Phoenix." You can't ever take a Wikipedia entry to be the gospel, but it is a corroborating piece of circumstantial evidence.Option C
Of course, Chastain may not be playing either of the characters above. The "Dark Phoenix Saga" has many alien characters - mainly The Shi'ar of the Shi'ar Empire. Chastain could be playing some wildly different version of the Shi'ar royalty (Lilandra, or Deathbird), or some other alien figure altogether. You never can tell with the X-Men movies what kind of changes will be made.
The X-Men Movie Universe continues with The New Mutants on April 13th; Untitled Deadpool Sequel on June 1st; and X-Men: Dark Phoenix on November 2nd.