The Marvel Cinematic Universe is preparing for another major reconfiguration, and familiar heroes across the franchise are weighing what comes next as Marvel charts its path forward. Disney has confirmed that December 19, 2025, will mark a key moment for the MCU.
Arriving in 2026, Avengers: Doomsday is shaping up to be one of Marvel Studios’ most ambitious projects to date. The film brings back Avengers: Infinity War (2018) and Avengers: Endgame (2019) filmmakers Anthony and Joe Russo, shifting away from the earlier Kang-focused direction and placing Doctor Doom at the center of the conflict, portrayed by Robert Downey Jr. in his long-anticipated return to the MCU.
Marvel launched 2025 with a “chair reveal” livestream, unveiling a sweeping ensemble that included Sebastian Stan (Bucky Barnes), Paul Rudd (Ant-Man), Simu Liu (Shang-Chi), Florence Pugh (Yelena Belova), Tom Hiddleston (Loki), Chris Hemsworth (Thor), Kelsey Grammer (Beast), and James Marsden (Cyclops).
The livestream also solidified the return of several iconic X-Men stars from the Fox era: Ian McKellen (Magneto), Rebecca Romijn (Mystique), Patrick Stewart (Professor X), and Alan Cumming (Nightcrawler). Their inclusion signals an expansive fusion of Marvel’s past and present cinematic universes.
Amid the fanfare, several longtime MCU actors addressed their absence from the new lineup. Mark Ruffalo, who has played the Hulk since The Avengers (2012), joked on The Tonight Show Starring Jimmy Fallon, “They decided that it was better to get rid of me than for me to tell the end of the next movie.”
Though Ruffalo is not part of Doomsday, he is already confirmed for Destin Daniel Cretton’s Spider-Man: Brand New Day (2026).
Brie Larson has remained especially measured when discussing her future as Captain Marvel. During an appearance on The View, when asked if she would be appearing in Avengers: Doomsday, she replied, “Thank you for asking, and you know I can’t answer.”
Her comment added momentum to ongoing theories that Carol Danvers may still play an important role in the upcoming event film. In 2024, Larson remarked, “I don’t have anything to say about that,” and in June 2025, she posted a cryptic image of herself next to the words “AVENGE” and “DANVERS.”
Larson last appeared in The Marvels (2023), which ended with Teyonah Parris’s Monica Rambeau trapped in another dimension and Carol vowing to bring her back.
Disney’s next major entry in the Avatar series, Avatar: Fire and Ash (2025), directed by James Cameron, arrives on December 19, 2025. Several reports indicate that Disney intends to use the release as the debut point for the first Avengers: Doomsday trailer.
“Collider has learned from multiple sources that the first footage from the MCU’s next big team-up film is scheduled to be attached to the latest installment of one of Disney’s other blockbuster franchises, Avatar: Fire and Ash,” the outlet reported.
If the plan holds, the teaser will drop exactly one year before the current December 18, 2026, premiere date for Doomsday. The rollout resembles the early reveal strategy used for Christopher Nolan’s The Odyssey teaser, which appeared a year ahead of its release in front of Jurassic World Rebirth (2025) and offered a character-focused moment instead of broad plot teases.
Now, just weeks after the initial reports, confirmation has arrived: the Avengers: Doomsday trailer will indeed premiere ahead of the Avatar threequel.
Avengers: Doomsday trailer is confirmed to be attached to Avatar 3.
Avengers: Doomsday trailer is confirmed to be attatched on Avatar 3. pic.twitter.com/zpSYe4bopQ
— MikeOnTheGrid 🥏 (@MikeTheProgram) December 11, 2025
I should also add that this trailer is 1 minutes and 27 seconds long. Contrary to the 60 seconds that was rumored.
I should also add that this trailer is 1 minutes and 27 seconds long. Contrary to the 60 seconds that was rumored.
— MikeOnTheGrid 🥏 (@MikeTheProgram) December 12, 2025
It’s a strategic move for Disney and Marvel, though it may frustrate fans who aren’t planning to see the latest Avatar or who feel the trailer is being used as an incentive to draw viewers into Fire and Ash screenings.
New promotional art for Avengers: Doomsday is also generating conversation about the future of Thor and Captain Marvel. A high-resolution piece displayed at the Walt Disney Studios Marketing Expo in Shanghai showcases Doctor Doom’s armor, featuring two symbols on the cloak fasteners.
One resembles Captain Marvel’s starburst emblem, and the other reflects Thor’s hammer, Mjolnir. Their mirrored placement has sparked speculation that these may represent trophies taken from Multiversal versions of the heroes rather than mere stylistic choices.
Although the imagery could be fully artistic, the details have fueled growing curiosity about Doom’s role and the scale of the changes Marvel is preparing to introduce.
Marvel Studios continues adjusting its roadmap as it heads toward Phase Six. 2025’s The Fantastic Four: First Steps debuted strongly before dropping sharply in its second weekend, underscoring the studio’s challenge of sustaining long-term audience momentum.
Still, Marvel president Kevin Feige and the Russo brothers have shared that Avengers: Doomsday and its follow-up, Avengers: Secret Wars (2027), will function as a creative reset for the MCU, placing the X-Men in a more prominent position and reshaping the franchise’s central lineup.
With Robert Downey Jr.’s Doctor Doom leading as the primary antagonist and a cast bringing together characters from multiple eras, Avengers: Doomsday may emerge as one of the MCU’s most defining chapter shifts yet.
How do you feel about the Avengers: Doomsday trailer coming soon? Let us know in the comments below!
