Sadie Sink might be stepping from Hawkins straight into the heart of the Marvel multiverse—but who exactly she’s playing is anyone’s guess. The excitement—and confusion—around her new roles has fans everywhere trying to piece together clues, but even the most dedicated theorists might be missing something crucial.
As Sadie Sink wraps up her Stranger Things era, she’s not leaving pop culture behind. Instead, she’s diving headfirst into the Marvel Cinematic Universe with confirmed roles in Spider-Man: Brand New Day and the upcoming Avengers: Doomsday. Both projects are massive, but here’s the twist: Marvel has yet to reveal which character she’s playing. Naturally, this secrecy has sparked an internet storm of speculation.
Could Sadie be taking on the role of Jean Grey, the telepathic powerhouse from the X-Men? Or maybe she’s playing Mayday Parker, the daughter of Spider-Man from an alternate timeline. Other fan-favorite guesses include Gwen Stacy or even the darker Madelyne Pryor. But here’s where things get controversial—some fans are already convinced based purely on her hair color. Yes, really.
In an interview with Deadline (link), Sink hinted that appearances can be deceiving, playfully teasing fans with a remark about misleading them: she might have even tweaked her look to keep people guessing. Later, speaking to Entertainment Weekly (link), she addressed the online frenzy: “A lot of people forget that hair color can change, but yeah, I understand all the theories. People will just have to wait and see. I’m excited for all of it to maybe be put to rest.”
When asked directly whether she’s portraying Jean Grey, her reaction was refreshingly candid: “That was happening before I even knew that I would be working on this project. I was like, ‘Wait! What are people talking about?’” Sounds like she’s as amused by the rumors as her fans are intrigued by them.
Spider-Man: Brand New Day is currently still in production and is expected to wrap filming by mid-December. The movie is helmed by director Destin Daniel Cretton, who previously brought Shang-Chi and the Legend of the Ten Rings to life, with a screenplay courtesy of Chris McKenna and Erik Sommers. Tom Holland returns as Peter Parker/Spider-Man, joined by a star lineup: Jon Bernthal reprises Frank Castle (Punisher), Mark Ruffalo steps in again as Bruce Banner (Hulk), Zendaya returns as MJ, and Jacob Batalon as Ned Leeds. Michael Mando is back as Mac Gargan (Scorpion), and Marvin Jones III joins as Lonnie Lincoln (Tombstone). Liza Colón-Zayas and Tramell Tillman round out the cast in yet-unknown roles.
But that’s only half the story. Before Secret Wars hits screens, the Marvel hype train continues with Avengers: Doomsday, boasting one of the most packed ensemble casts in superhero history. The lineup includes Chris Hemsworth as Thor, Vanessa Kirby as Sue Storm, Sebastian Stan as Bucky Barnes, Letitia Wright as Shuri, Anthony Mackie as Captain America (Sam Wilson), and Paul Rudd as Ant-Man. Other big names joining the team: Wyatt Russell (John Walker), Tenoch Huerta Mejía (Namor), Ebon Moss-Bachrach (Ben Grimm), Simu Liu (Shang-Chi), Florence Pugh (Yelena Belova), Kelsey Grammer (Beast), Lewis Pullman (Bob), Danny Ramirez (Joaquin Torres), Joseph Quinn (Johnny Storm), David Harbour (Red Guardian), Winston Duke (M’Baku), Hannah John-Kamen (Ghost), Tom Hiddleston (Loki), Patrick Stewart (Professor X), Ian McKellen (Magneto), Alan Cumming (Nightcrawler), Rebecca Romijn (Mystique), James Marsden (Cyclops), Channing Tatum (Gambit), Pedro Pascal (Reed Richards), and—perhaps the biggest shock—Robert Downey Jr. returning in a new role as Victor von Doom.
Avengers: Doomsday is slated to hit theaters on December 18, 2026, paving the way for Secret Wars a year later, on December 17, 2027.
For now, all eyes are on Sadie Sink and the mystery that surrounds her Marvel debut. Could her role redefine the MCU’s future, or will it subvert fan expectations entirely? Either way, fans are bracing for something special. What do you think—should Sadie play a hero, a mutant, or maybe even a villain? Sound off in the comments—this debate is only just getting started.