As excited as I am to see classic X-Men actors in Avengers: Doomsday, I do think it could create an MCU problem in the future. The next major crossover promises to be a big multiversal epic with heroes from various realities. However, I’m worried the short-term benefits of some exciting cameos may create some weird dynamics in the long term.

It’s unlikely that the entire cast of Avengers: Doomsday has yet to be fully announced. That said, multiple X-Men characters/actors from the Fox universe of films are already confirmed, and will soon be joining the Avengers from the main MCU timeline and more heroes in a battle against Robert Downey Jr.’s Doctor Doom. However, I’m realizing that the original live-action X-Men being in Avengers: Doomsday may cause some odd problems down the line.

Multiple Original Fox X-Men Characters Will Soon Meet The MCU’s Avengers

Professor X, Magneto, Cyclops, and More

Marvel Studios’ recent live-stream video confirmed several different MCU actors for Avengers: Doomsday, culminating in Robert Downey Jr. at the end of a long line of chairs with each actor’s name on them. This included various Avengers, Thunderbolts*, The Fantastic Four, Wakandans, and more heroes. However, the most surprising names were definitely the seven different X-Men actors confirmed to be included in Doomsday.

Thus far, Professor X (Patrick Stewart), Magneto (Ian McKellen), Cyclops (James Marsden), Mystique (Rebecca Romijn), Nightcrawler (Alan Cumming), Beast (Kelsey Grammer), and Gambit (Channing Tatum) have all been confirmed to be appearing in Avengers: Doomsday. Aside from Channing Tatum’s Gambit who debuted in 2024’s ᴅᴇᴀᴅpool & Wolverine, these names are all from the original X-Men cast, before Fox rebooted their timeline with a younger cast including James McAvoy as Xavier, Michael Fᴀssbender as Magneto, and more. As such, it’s expected that all of these X-Men (and likely more mutants) will soon encounter the Avengers from the main MCU timeline of Earth-616.

What’s Going To Happen When Marvel Studios Finally Introduces Their Own Cast of X-Men?

Will The Avengers Already Have History With Different Mutant Heroes?

Without a doubt, having X-Men and Avengers fighting together for the first time in live-action is an incredibly exciting prospect. Who wouldn’t want to see Cyclops and Captain America leading their respective teams into battle, with audiences potentially getting to hear “Avengers ᴀssemble!” and “To Me, My X-Men!” in the same movie? There are also some great opportunities for great character dynamics never seen on-screen before, like Reed Richards’ Mister Fantastic getting to compare notes with Hank McCoy’s Beast, or even just getting the chance for James Marsden’s Cyclops to get the spotlight (and yellow and blue costume) he’s always deserved.

That said, one has to wonder what kind of impact these interactions in Avengers: Doomsday might have on the MCU’s future. After all, it’s largely expected that Marvel Studios will eventually debut their own cast of X-Men with new actors and characters that are native to the Earth-616 timeline. What’s it going to look like when and if the Avengers one day interact with new X-Men who also call the same world home, having already met and fought alongside their Fox counterparts from another live-action Marvel universe in Doomsday?

One could argue that this issue could very well be moot if the entire MCU is rebooted following the end of the Multiverse Saga with 2027’s Avengers: Secret Wars. There would be a blank slate and a fresh start for all Marvel live-action heroes, Avengers and X-Men alike. That said, I’m not confident that Marvel Studios is willing to fully reboot and start completely over, abandoning what will be almost 20 years of interconnected storytelling.

The multiverse will probably look very different in the aftermath of the next two MCU movies. However, the events of the past will likely still remain canon, including what will be the Avengers’ history with the original cast of X-Men. Overall, my concern is that the MCU is going to create some odd dynamics with any new mutant who had a Fox counterpart who participated in Avengers: Doomsday and/or Secret Wars.

I Think There Will Be A Long-Term Cost After Secret Wars For The MCU X-Men

Potentially Weird Future Dynamics For The Sake of Short-Term Crossover Benefits

It’s also worth noting that the upcoming team-up will likely invite an increased level of comparison to what came before when the new X-Men cast does debut. That’s something you’d think Marvel wouldn’t want as they move to embrace a new era for mutantkind in the main MCU. Ultimately, Marvel’s decision to bank on the nostalgia of Fox’s pre-existing X-Men does make lots of sense in the short term, considering the multiverse and the next two crossovers. However, I think it could create some long-term funkiness once Marvel’s ready to finally debut their own mutant heroes.

In summary: ᴀssuming the MCU doesn’t do a full reboot after Secret Wars (which feels highly unlikely), the odds are good we’re going to have Avengers eventually interacting with a new native MCU cast of X-Men…after they’ve already interacted with the OG Fox versions in Doomsday. I think both Marvel Studios (and fans) need to prepare for that eventuality, and the weirdness that will come with it. For example, how are the Avengers going to respond to a brand-new Xavier or a villain like Magneto, when they will have already fought side by side with both to save the multiverse from Doctor Doom?

It’s an intriguing question, and one that could get real messy real fast. As a possible alternative, perhaps a new MCU is created in Secret Wars’ aftermath, one based off the MCU we’ve always known but with some slight variations (mirroring the original 2015 comics event). One of those changes could be that mutants and the X-Men have always been a part of the timeline, and the memories of characters will be altered to reflect that fact. It’s just a theory, though it does help circumvent the potential aforementioned weirdness of Avengers meeting multiversal variants of X-Men first.

Avengers: Doomsday releases May 1st, 2026 from Marvel Studios.

Upcoming MCU Movies

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  Captain America: Brave New World

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  February 14, 2025
  

  
  
  
  

  
  

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  Thunderbolts*

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  May 2, 2025
  

  
  
  
  

  
  

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  The Fantastic Four: First Steps

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  July 25, 2025
  

  
  
  
  

  
  

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  Avengers: Doomsday (2026)

  
  
  
  
  

  
  

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  Spider-Man: Brand New Day

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  July 31, 2026
  

  
  
  
  

  
  

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  Avengers: Secret Wars

  Release Date

  
  May 7, 2027
  

  
  
  
  

  
  

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