Marvel Studios' Avengers: Doomsday is expanding the playing field once again, bringing in another universe to the mix in December 2026. The film has already been confirmed to feature the newly introduced Fantastic Four alongside returning faces from the Fox-era X-Men films, both coming from separate universes from the Sacred Timeline. With a fifth universe now in the mix, it's becoming clear that Marvel is positioning this blockbuster as one of the most ambitious crossover events in the MCU's history...and this may only be the beginning.
News recently broke that Ryan Reynolds' Deadpool would be joining Avengers: Doomsday. Initially, he shared a graffitied image on Instagram of the Avengers logo, which was later corroborated by The Hollywood Reporter. While this isn't a confirmation from Marvel Studios, and Reynolds did not receive an infamous chair back in April, it's safe to assume Deadpool is coming back for Avengers 5.
Based on that assumption, Avengers: Doomsday has just added its fifth universe to the film.
The Doomsday cast is expected to be expansive, to say the least, based on some reports, over 60 MCU and past Marvel characters could appear in the film.
In terms of plot, there isn't much to go on. Doctor Doom (presumably Robert Downey Jr.) appeared in The Fantastic Four: First Steps post-credits scene, and we know that team from Earth-828 somehow makes their way to Earth-616, based on the Thunderbolts* post-credits scenes. The issue, which won't be answered until its release in theaters, is that fans currently don't know the who, what, where, when, or why of the upcoming Avengers-level threat.
The most useful rumor that is swirling following the release of First Steps is that Doctor Doom will seek out baby Franklin Richards because he is key to stopping multiversal incursions. According to the report, Doom will see himself as the "hero" of the story, much like Thanos (Josh Brolin) in Avengers: Infinity War.
When it comes to incursions in the MCU, he concept was first introduced in Doctor Strange in the Multiverse of Madness, where Reed Richards (John Krasinski) explained them as catastrophic events that occur when two universes collide.
Clea's (Charlize Theron) mid-credits warning to Strange (Benedict Cumberbatch) that he had caused an incursion cemented the idea as a major danger. Since then, incursions have been hinted at in Ant-Man and the Wasp: Quantumania and directly shown on-screen in The Marvels' post-credits scene, where Monica Rambeau (Teyonah Parris) experienced reality breaking apart and jumped to one of the five universes expected to appear in Doomsday on December 16, 2026.
Earth-616 / Earth-199999
This is the core MCU timeline, where the Avengers, the New Avengers, and most of our familiar heroes reside. Of the confirmed cast members and characters, Anthony Mackie's Captain America, Florence Pugh's Yelena, Letitia Wright's Black Panther, and maybe even Tom Holland's Spider-Man will lead from this world.
Earth-616, as it was designated in Doctor Strange in the Multiverse of Madness, was the only reality known to Earth's defenders throughout the Infinity Saga, until time was meddled with in Avengers: Endgame.
Earth-10005
Earth-10005 refers to the universe that hosted the 20th Century Fox X-Men franchise, concluding with Deadpool & Wolverine.
With Ryan Reynolds set to appear in Avengers 5, this universe is the latest to be added to this list of realities expected to appear in the movie. In Deadpool & Wolverine, both Deadpool and Logan (Hugh Jackman) stay in this universe after preventing its destruction, even though this version of Wolverine comes from an entirely different universe.
Earth-828
Earth-828 is the new 1960s-styled universe introduced in The Fantastic Four: First Steps. It offers a retro-futuristic setting inspired by Jack Kirby's designs. In fact, its numeric designation is a tribute to Kirby's birthday (8/28).
In this world, the Fantastic Four are already heroic icons defending against Galactus and the Silver Surfer. This self-contained timeline avoided continuity issues with the main MCU, creating freedom from prior narrative ties.
However, the film connects to Avengers: Doomsday through a mid-credits cameo of Doctor Doom, and worlds could begin to literally collide next year.
Earth-Unknown (Original X-Men)
A familiar lineup of classic X-Men actors is confirmed to return, but not from Earth-10005 (where many, if not all, of their characters are dead).
Instead, these characters appear to come from the reality glimpsed in The Marvels' post-credits scene: Charles Xavier (likely another version of Patrick Stewart) is alive, and Beast (portrayed by Kelsey Grammer) is confirmed to join Doomsday.
This suggests the presence of yet another X-Men universe that remains distinct from both the Fox universe and the MCU's mainstream timeline. In some respects, this mystery universe could be one of many that ultimately appear in the film, especially given the variety teased in Doctor Strange in the Multiverse of Madness.
Loki's World Tree
The World Tree isn't a traditional universe but represents a realm outside standard space and time.
In the finale of Loki Season 2, Loki reshapes the multiverse into a form resembling the cosmic Norse World Tree, Yggdrasil, cementing his role as the "God of Stories" and the multiverse's guardian.
With Hiddleston's confirmation to return as a "new" Loki in Avengers: Doomsday, this multiversal overseer is expected to play a crucial part in the battle after making such a sacrifice last time audiences saw him.
BONUS: The Void
The Void is another immersive location outside of time and space expected to return in Avengers: Doomsday.
First seen in Loki Season 1, the Void is where Loki meets multiple Variants while fleeing from Alioth. The Void later served as a refuge in Deadpool and Wolverine, where Deadpool and Wolverine faced off against Emma Corrin's Cassandra Nova.
According to insider reports, filming for Doomsday includes scenes set in The Void, marking its MCU, possibly becoming intermixed with the Battleworld concept from Marvel Comics.
