Insider reports are swirling that Marvel’s next big chapter—Phase 7—will kick off with one of the X-Men’s darkest villains, Mr. Sinister. According to industry leaker Daniel Richtman, the studio plans to slot Nathaniel Essex’s first appearance right after Avengers: The Kang Dynasty and Spider-Man: Brand New Day. If confirmed, this would be the MCU’s first true X-Men tentpole, officially launching the mutant saga long teased in Easter eggs and post-credits cameos.
Since Disney’s acquisition of Fox, Marvel Studios has purposefully peppered in brooding mutant hints—from the blink-and-you’ll-miss-it nods in Doctor Strange in the Multiverse of Madness to mutant glyphs in Ms. Marvel. Yet no dedicated X-Men film has ever fully materialized. With Deadpool’s R-rated romp on deck, industry eyes are now trained on Sinister, a genetically obsessed villain who could ground the mutant era in a darker, more visceral tone.
Created by Chris Claremont and Marc Silvestri in 1988, Mr. Sinister is far more than a mustache-twirling scientist. Essex’s telepathy, shapeshifting and penchant for human experimentation bring body-horror chills rarely seen in the brightly colored MCU. His morally ambiguous experiments on the Summers and Grey bloodlines add layers of secret-lab intrigue. On the big screen, Sinister could push Marvel’s visuals and themes into bold new territory—think gothic laboratories, genetic monstrosities and high-stakes ethical dilemmas.
Marvel reportedly has tapped Jake Schreier—fresh off helming Thunderbolts—to steer Sinister’s origin story. Schreier has talked about marrying blockbuster scale with character-driven storytelling, but fans are eager to see if he’ll lean into the horror elements essential to Essex’s unsettling legacy. Veteran producer Victoria Alonso once observed that “the mutant mythos rewards risk,” and under her watch, Marvel is expected to assemble a creative team ready to blur the line between superhero spectacle and gothic thriller.
Marvel’s mutants have thrived in video games—from the cult-classic X-Men Legends to the strategy-RPG style of Marvel’s Midnight Suns. Rumors suggest a Mr. Sinister expansion could arrive as post-launch content for Midnight Suns, or he might cameo in the upcoming Deadpool title. Coordinated release windows could let fans trace Sinister’s machinations across screens and controllers, creating a unified, cross-platform narrative powerful enough to launch the mutant era.
Insiders say Sinister’s film will anchor the start of Phase 7 before mutants bleed into other MCU properties like Black Panther 3 or an ensemble X-Force outing. Marvel EVP Nate Moore has emphasized seamless integration—so expect strategic tie-ins with Doctor Strange, the Fantastic Four, and even a potential mutant Avengers lineup. Casting whispers include veteran character actors to anchor the post-credits web of mutant plots.
Mutant narratives have always resonated with real-world themes of prejudice, identity and belonging. Introducing Mr. Sinister as the catalyst for Phase 7 signals Marvel’s intent to deepen its storytelling and embrace a darker edge. When combined with synchronized video game content, a well-executed Sinister film could redefine cross-media synergy, setting a new benchmark for how franchises expand beyond the multiplex.
Sources: Daniel Richtman’s Patreon, Variety interviews, Marvel Studios statements.