X-Men: Dark Phoenix: Is Jessica Chastain Really Playing Mr. Sinister?

Mr. Sinister might be switching up their pronoun preference in the next X-Men movie, according to a compelling new rumor making the rounds.

According to Jeff Sneider, editor-in-chief of The Tracking Board, the identity of Jessica Chastain's mysterious villain character in the upcoming X-Men: Dark Phoenix might be one of the last characters we would expect. 

Speaking on the March 30 episode of podcast Meet the Movie Press, Snieder took an moment to acknowledge a rumor that Chastain's character is a gender-swapped version of the X-Men villain Mr. Sinister.

"What if — forget the pronouns, here — what if Jessica Chastain was playing Mr. Sinister?" he said. "That's the rumor."

Though Sneider went on to classify the rumor as only "a possibility", the rumor is so specific and strange that it merits some consideration — and there's a lot of evidence in the comics to support it.

Mr. Sinister is a geneticist named Nathaniel Essex, an ageless character born in Victorian England. His wide variety of mutant powers, including teleportation, telepathy, telekinesis, and rapid healing, make him one of the few villains who could be a credible threat to the powerful force that is the Phoenix — but that's not the only reason this rumor is so interesting.

In the X-Men comics, there is a female character by the name of Miss Sinister, a genetic clone of Mr. Sinister that was created as a sort of fail-safe to be deployed in the event of his death. 

Miss Sinister, whose real name is Claudine Renko, was originally a normal woman in the comics, not always genetically connected to the supervillain. Instead of being born inside a test tube, she became a genetic duplicate of Mr. Sinister through the injection of a virus containing his DNA and power set. As a result of the injection, Mr. Sinister slowly took over Renko's mind, self-resurrecting by destroying her identity, imposing his will over her own.

In reporting the rumor, Sneider was very specific in calling the character a "Mr." — which would technically be true if he was the villain in Renko's mind, battling for control of her body. That sort of villain story would work as a great parallel for the story of Jean Grey, who is battling for control of her body against the invading power of the Phoenix Force. 

The Mr./Miss Sinister concept also tracks with what we know about the movie's plot, which previously identified Chastain as playing a villainous, otherworldly shapeshifter. For what it's worth, Mr. and Miss Sinister's most notable power in the comic books is — you guessed it — shapeshifting.

All of this conjecture brings us to where we are now: still in the dark, but with some interesting new information. For what it's worth, Mr. Sinister was previously teased in the post-credits scene to X-Men: Apocalypse, which heralded the coming of the villainous "Essex Corp."

Chastain's role in Dark Phoenix has been a constant moving target ever since her casting was announced. At first, it was reported with near-certainty that the actress was taking on the role of the villain Lilandra in the sequel, leading an intergalactic quest to capture or otherwise neutralize the Phoenix. 

But Chastain appeared to throw water on those reports when she wrote on her own Instagram page that she wasn't playing Lilandra. However — making things more complicated — that post has since been deleted. 

Everyone's trying to pin down the identity of Chastain's character, and she's out here juking and faking and dodging like a champ. She's so skilled at keeping us in the dark that it's almost downright... sinister.

X-Men: Dark Phoenix will be out in theaters on February 14, 2019.