Evidence is mounting that Sadie Sink is playing one of the most beloved X-Men heroes in Spider-Man: Brand New Day and the MCU's Phase 7 reboot. One of Brand New Day's biggest mysteries still surrounds who Stranger Things star Sadie Sink will portray in the July blockbuster. Of the many theories, arguably the most prominent is X-Men icon Jean Grey, a telepathic hero who famously bonds with the Phoenix Force to become one of Marvel's most powerful beings.
Spider-Man 4 will feature the Department of Damage Control (DODC), led by Tramell Tillman's mystery character, on the hunt for Sink's super-powered character. As rumors indicate that the DODC will soon be tracking down mutants in the MCU, it's not out of the realm to say that Sink could be playing one herself.
MCU fans just saw the DODC tracking down one beloved hero, Yahya Abdul-Mateen II's Simon Williams, in Wonder Man. While the origin of Williams' ionic powers is never revealed in the Disney+ series, Marvel Studios considered making the MCU's Wonder Man a mutant ahead of the X-Men reboot.
There is evidence to suggest that Sink could be playing Grey, beyond her red hair and her fit for the MCU's younger X-Men casting. For one, insider Daniel Richtman stated that the mystery Brand New Day character will have "mind-control powers," with Grey known as one of Marvel's most powerful telepaths.
Furthermore, scooper MyTimeToShineHello claimed that Sink will be wearing green and yellow attire in Brand New Day, which just so happens to be the colors iconically worn by Grey for many years in comics and animation.
In December 2024, just four months before Sink was announced for 2026's Spider-Man flick, Jeff Sneider reported that Marvel Studios was eyeing the Stranger Things star to play the X-Men icon Jean Grey. It's certainly tough to dismiss that timing as coincidental, and it only adds further credence to the theories.
If the theory proves true, Sink would join Sophie Turner and Famke Janssen as the third major actress to play the role in X-Men movie history.
Sadie Sink Might Have a Huge MCU Future
As Marvel Studios stays silent on Sadie Sink's character, it was reported that she will reprise her Brand New Day role in Avengers: Secret Wars. With the Multiversal epic promised to usher in a new beginning for the MCU, including the X-Men reboot, it would only make sense for the mutant telepath to appear.
In rebooting the X-Men for a new generation, Marvel Studios will be eager to secure at least a few big names to front the Phase 7 blockbuster. There's no denying that, off the back of Stranger Things, Sink has proven her stardom and acting prowess enough to carry such a major role.
Sink, alongside whoever gets cast as Scott Summers, aka Cyclops, could potentially be the two faces of the MCU's X-Men reboot. A leading X-Men role could put the Stranger Things veteran at the heart of the MCU for the next decade, possibly culminating with one day starring in yet another Dark Phoenix adaptation.
