The Marvel Mutant Sadie Sink Could Be Playing In Brand New Day If She’s Not Jean Grey

The prevailing theory regarding Sadie Sink’s character in Spider-Man: Brand New Day is that the actress is about to bring Jean Grey into the Marvel Cinematic Universe. The apparent presence of mind control elements in Spider-Man’s upcoming MCU outing has only added fuel to those discussions.

However, Marvel has yet to offer any confirmation as to who Sink is playing, and talk of Jean Grey appearing in Brand New Day is still just speculation at this point. Even so, the X-Men heroine remains a huge talking point for the film, despite the notion that a Spider-Man film would be a surprising choice for Jean Grey’s MCU debut.

A big part of what’s behind these rampant theories is the knowledge that Sadie Sink will appear in both Brand New Day and Avengers: Doomsday, not to mention the lingering secrecy behind the identity of her character. That does create the impression that Sink is playing a character of significant importance either to Spider-Man lore or the wider MCU, and Jean Grey would certainly check the latter box.

Sadie Sink Could Be Playing Firestar, A Character With Important Spider-Man & X-Men Connections

Although not as exciting as the prospect of Jean Grey joining the MCU, Firestar is a potential candidate for Sadie Sink’s Brand New Day character. Angelica Jones a.k.a. Firestar famously made up one third of the trio of superheroes featured in the 1980s animated series, Spider-Man and his Amazing Friends, with Peter’s other ally being Iceman.

Unlike Spider-Man and Iceman, Firestar was a brand-new addition to the Marvel Universe. But naturally, she did not remain exclusive to the show and was quickly added to the comics. True to her role in the cartoon, the comic book version of Firestar is a red-headed mutant with the ability to manipulate radioactive energy.

Firestar became a founding member of the New Warriors team and also served as a member of the main Avengers team in the late 1990s. And due to her mutant status, she’s been utilized as a recurring character in various X-Men titles as well.

Although she’s been around for decades, Angelina Jones continues to be an under-the-radar Marvel character. That said, Marvel hasn’t shied away from introducing live-action takes on its B and C-list superheroes before, and could easily do so again. And her connection to Spider-Man, albeit one that’s rooted primarily in a cartoon, is certainly big enough to justify her showing up in Brand New Day.

And with her red hair being her key, distinguishing characteristic, Sadie Sink would absolutely fit the part physically, just as she would if her character was revealed to be Jean Grey.

How Firestar Could Fit Into Spider-Man: Brand New Day’s Story

As for what she’d be doing in Spider-Man: Brand New Day, Firestar’s microwave radiation powers could be what’s behind her relevance to the plot. The Spider-Man: Brand New Day trailer has revealed that Spider-Man will develop organic webbing due to mutations in his DNA, which points to “The Other” possibly being the comic inspiration for the story.

In “The Other,” Spider-Man receives the same abilities, but as a consequence of a fatal, radiation-induced disease. Firestar could be a factor here, either as the cause or a possible cure, if it’s true that Brand New Day is adapting this particular storyline.

A simpler alternative is that Firestar could be a new love interest and fellow superhero that Peter meets during his adventures in Spider-Man: Brand New Day. And since Firestar does have ties to the Avengers, she could join the current iteration of Earth’s Mightiest Heroes ahead of the battle with Doctor Doom in Avengers: Doomsday.