Well, There Goes My Marvel Theory About The Avengers Fighting The X-Men In Doomsday

Well, it seems as though we might not be getting the Avengers vs X-Men adaptation I was hoping for in the MCU. Following the live stream reveal confirming multiple X-Men actors for the cast of Avengers: Doomsday, theories began to fly about how the Fox universe’s heroes would be involved. However, it seems as though the biggest one has just been debunked.

Currently, not much is known about the plot of Avengers: Doomsday, beyond the fact that Robert Downey Jr. is set to return to the MCU as Doctor Doom, the movie’s primary villain. Doomsday will also precede Avengers: Secret Wars, which will conclude the current Multiverse Saga. To that end, it’s not surprising that the confirmation that 7 different X-Men actors are set to appear in Doomsday sparked so much surprise, excitement, and speculation. However, it seems Marvel Studios’ Kevin Feige just upended my big theory about a potential Avengers vs X-Men storyline.

I’ve Wanted To See Avengers vs X-Men In The MCU For A Long Time

I’ve Literally Been Waiting Since 2012

2012 was a very big year for Marvel, both for the MCU and the comics. Firstly, it saw the theatrical release of the very first Avengers movie, a groundbreaking endeavor for crossover films and the first true sign that an interconnected cinematic universe of movies could do wonders at the box office, capturing the attention of comic book fans and general audiences alike. Likewise, 2012 also saw the publication of Avengers vs X-Men on the page, a very popular and successful crossover where Earth’s Mightiest Heroes went to war with mutants over the return of the Phoenix Force.

10 Biggest Comic Team-Ups & Rivalries From The Avengers: Doomsday Cast

The first wave of Avengers: Doomsday cast announcements have confirmed that we’re more than likely going to see some major team-ups and/or rivalries.

While the Avengers feared the Phoenix’s power to destroy, the X-Men saw its potential to create and revive mutantkind, which at the time was nearly extinct. The release of both incredibly exciting projects ignited my hopes that we might one day see the Avengers and X-Men duking it out in live-action. This was even before the introduction of the multiverse in the MCU, which has now made it easier than ever for Fox’s X-Men and Marvel Studios’ heroes to encounter each other, join forces, and perhaps even fight.

I Was Convinced Doomsday Would Finally Give Us Avengers vs X-Men

Adapting The Comic Story With Some Multiversal Twists

Captain America and Gambit MCU Avengers Domsday With Avengers vs X-Men Background Custom Image — Custom Image by Kevin Erdmann

Marvel Studios’ live-stream event confirmed that various original X-Men heroes are set to appear in 2026’s Avengers: Doomsday. This includes Professor X (Patrick Stewart), Magneto (Ian McKellen), Cyclops (James Marsden), Mystique (Rebecca Romijn), Nightcrawler (Alan Cumming), Beast (Kelsey Grammer), and Gambit (Channing Tatum) who recently made his debut in 2024’s Deadpool & Wolverine. It’s also been confirmed that the live-stream event did not reveal the entire cast, so there could very well be even more mutant heroes on the way for next year’s major MCU crossover.

Most of these X-Men characters are from the original Fox universe/timeline (though Gambit is more adjacent). As such, the big theory that I and many others had was that the Fox universe might take the place of the Ultimate Universe as the MCU adapts Secret Wars and its prelude story, Time Runs Out. In the comics, the Ultimate Universe and the main Marvel Universe were the last two realities yet to be destroyed via a multiversal incursion.

As the two Earths collide with the promise of nothingness in their wake, Doctor Doom harnesses immense power to save existence itself, creating a patchwork realm of fragmented realities known as Battleworld, where he rules as God Emperor. With Fox’s X-Men replacing the Ultimate heroes, they would fight the Avengers for the survival of their respective realities, effectively adapting elements from Times Runs Out/Secret Wars and 2012’s Avengers vs X-Men. Doom would then act as a savior by creating Battleworld and setting up Secret Wars in 2027. However, new comments from Kevin Feige have certainly cast some doubts on my AvX dreams.

Multiple Teams Joining Forces Against Doctor Doom

During Disney’s presentation at CinemaCon 2025, a video message from Kevin Feige saw the Marvel president providing some key updates as new footage was revealed for Thunderbolts* and Fantastic Four: First Steps. From the set of Doomsday, Feige also gave some small insights about the new movie coming next year as well. Confirming that the movie’s cast has yet to be fully announced, Feige also revealed that Doomsday will feature multiple teams of heroes coming together to fight Doctor Doom: The Avengers, the Wakandans, The Fantastic Four, The Thunderbolts, and the original X-Men.

With that in mind, the promise of unified teams certainly dampens my hopes of an all-out brawl between the Avengers and X-Men in the MCU. That said, how many times have superhero team-ups started out with an initial fight? It’s practically a prerequisite, though more than likely not to the full scale I was initially hoping for. That said, the idea of multiple teams having to take on one singular villain is still all kinds of exciting.

How The MCU Could Still Give Us Avengers vs X-Men

We May Have To Wait For The Presumed Mutant Saga…

X-Men could be coming in MCU Avengers Secret Wars

While it might not be happening in Doomsday, perhaps there’s still hope for an Avengers vs X-Men battle in Secret Wars. Based on the comics, the possibilities are endless, as multiple conflicts were happening all at the same time across various fiefs and territories as Doom ruled over it all with an iron fist. That being said, it’s just as likely that Marvel Studios is more interested in saving something as big as Avengers vs X-Men for the future, once the Multiverse Saga has been well and truly wrapped up.

Although not confirmed by any means, there’s a big expectation that the next phase of MCU movies will largely be a mutant saga as Marvel Studios brings brand-new actors to play new X-Men in their interconnected universe, once they’ve presumably used the multiverse to fully close the door on the preexisting Fox universe. With that in mind, it’s certainly possible that Marvel Studios is holding back on Avengers vs X-Men until they can have new MCU mutants to fight Earth’s Mightiest, though time will tell.

Avengers: Doomsday is set to release in theaters on May 1st, 2026 from Marvel Studios.