The highly anticipated film, Avengers: Doomsday, has unveiled another teaser trailer following the theatrical run of Avatar: Fire and Ash, offering audiences their most comprehensive look yet at the exciting integration of the X-Men into the Marvel Cinematic Universe's grand team-up event. This latest trailer is the third in a series of four weekly releases by Disney, building on earlier spotlights on Chris Evans and Chris Hemsworth, and further intensifying anticipation for the multiversal conflict.

A significant highlight of the new trailer is the prominent display of the original 20th Century Fox X-Men characters, making a dramatic return. Earlier this year, the precedent for their involvement was set with the reveal of actors like Patrick Stewart as Professor X, Ian McKellen as Magneto, Kelsey Grammer as Beast, Alan Cumming as Nightcrawler, Rebecca Romijn as Mystique, and James Marsden as Cyclops. Many of these stars haven't reprised their superhero roles in decades, with only Stewart and Grammer having made brief appearances in the MCU previously. The film is dedicated to honoring their cinematic legacy, featuring comic-accurate costumes that promise to make their crossover into the Multiverse Saga a memorable experience for long-time fans.

These iconic mutants will have the opportunity to interact with an extensive roster of Marvel veterans, including Benedict Cumberbatch, Letitia Wright, Tenoch Huerta, Simu Liu, Paul Rudd, and Tom Hiddleston. Furthermore, the narrative will expand to include other major teams such as the Thunderbolts and the Fantastic Four, alongside Channing Tatum's Gambit, who will make his debut following his appearance in Deadpool & Wolverine.

While the X-Men take center stage in this new teaser, the film's primary antagonist, Robert Downey Jr.'s Doctor Doom, remains largely shrouded in mystery. His return to the MCU as the formidable villain is a major factor in Doomsday's status as one of 2026's most anticipated films, especially with reports of a substantial payday exceeding $100 million for the actor. His connection to Marvel's first family, the Fantastic Four, was subtly teased in the mid-credits scene of The Fantastic Four: First Steps, where he loomed over Reed Richards (Pedro Pascal) and Sue Storm's (Vanessa Kirby) baby, Franklin. Downey Jr.'s seeming confirmation about "getting Victor Von Doom right" reinforces that he will indeed be portraying the Latverian ruler, dispelling earlier speculations of him being a darker Iron Man mirror. The MCU is deliberately maintaining ambiguity around his motivations, keeping fans guessing until the film's release.

Robert Downey Jr.'s commitment extends beyond Doomsday, with his involvement also confirmed for the Russo Brothers' second half of the crossover epic, Avengers: Secret Wars. This aligns with earlier statements from Captain America: Brave New World star Anthony Mackie, who teased a cliffhanger ending for Doomsday. Plot specifics for both films are being kept strictly confidential, though Mackie ominously warned viewers that "Everyone is expendable." Other notable actors seemingly confirming their roles include Paul Bettany as Vision and Sadie Sink, heavily implied to join as her mystery character from Spider-Man: Brand New Day. More significant casting announcements are anticipated as the release dates approach.

Avengers: Doomsday is set to premiere in theaters on December 18, 2026. Directed by Anthony and Joe Russo and written by Stephen McFeely, Michael Waldron, Jack Kirby, and Stan Lee, the film features a stellar cast including Chris Hemsworth as Thor, Vanessa Kirby as Sue Storm / Invisible Woman, Joseph Quinn as Johnny Storm / Human Torch, and Ebon Moss-Bachrach as Ben Grimm / The Thing. Audiences can look forward to one final trailer accompanying screenings of Avatar: Fire and Ash next week, with Collider promising continued coverage of this monumental MCU crossover event.