Marvel Studios has found itself battling another round of online leaks after a third teaser for ‘Avengers: Doomsday’ surfaced on social media, offering the clearest indication yet that the X-Men are finally set to make their full debut within the Marvel Cinematic Universe.
The short clip, which began circulating late on Sunday, appears to have been recorded inside a cinema and quickly spread across multiple platforms before being taken down. Despite its poor original quality, the footage has generated intense discussion among fans for its focus on two iconic figures from the X-Men franchise.
The teaser opens on a devastated Xavier School for Gifted Youngsters, engulfed in flames, while a voice believed to be Patrick Stewart reflects on survival in the aftermath of a catastrophic conflict. Stewart is then briefly seen as Professor Charles Xavier alongside Ian McKellen’s Magneto, marking their most prominent appearance together in an MCU-linked project to date.
The footage also hints at large-scale destruction, including a moment involving Sentinels attacking unseen targets. One of the teaser’s most talked-about sequences shows Cyclops unleashing a powerful optic blast, a depiction many fans have described as the most visually striking portrayal of the character on screen so far.
By Monday morning, the leaked video had evolved further online, with several accounts sharing enhanced and AI-upscaled versions of the footage, allowing clearer views of key moments and characters. Reaction has been overwhelmingly positive, with viewers suggesting the X-Men-focused teaser has eclipsed earlier leaked promos that hinted at the return of characters such as Steve Rogers and Thor.
The X-Men film series was previously produced by 20th Century Fox after the studio acquired the rights to the characters in the 1990s. Their long-anticipated integration into the MCU has been a major talking point since Disney’s acquisition of Fox in 2019.
Avengers: Doomsday is shaping up to be one of Marvel’s most ambitious projects to date. The film will see Robert Downey Jr return to the franchise in a new role as the villain Doctor Doom, with the story reportedly spanning multiple universes. The ensemble cast also includes Anthony Mackie, Sebastian Stan, Paul Rudd, Tom Hiddleston, Letitia Wright, Simu Liu, Florence Pugh and Pedro Pascal, among others.
Marvel Studios has not commented on the leaked footage. Avengers: Doomsday is currently scheduled for release in December 2026.
