The cast announcement for Avengers: Doomsday has significantly impacted the future of the MCU, but it also sheds light on its immediate past – specifically, the Captain America: Brave New World post-credits scene. Marvel aired a surprise announcement last week with a live stream that turned out to be an official cast reveal for one of the MCU’s most anticipated upcoming movies, Avengers: Doomsday. This established a whopping 27 cast members for Avengers: Doomsday, though prevailing theories suggest there are more to come.

Whatever the case, it is great to see that Marvel Studios is getting the ball rolling on one of its biggest cinematic events in recent years. The Avengers: Doomsday lineup dominated online conversation for the entire day when it aired last week and will hopefully keep that momentum going in the following months as further cast members are announced and questions such as whether Marvel spoiled Thunderbolts* are answered. For now, with speculation at an all-time high, I think the announcement itself has already answered a burning question that has been floating since February.

Marvel’s Avengers: Doomsday Cast Includes Original X-Men Actors

Six Actors From Fox’s Original Franchise Were Revealed

While the Avengers: Doomsday cast reveal included a number of expected actors, including Chris Hemsworth and the cast of The Fantastic Four: First Steps, things started to get really interesting when Kelsey Grammer’s name appeared on one of the cast chairs. Grammer’s Hank McCoy, AKA Beast, was last seen interacting with Earth-616’s Monica Rambeau in The Marvels‘ post-credits scene, where he also references Charles, whom we can all safely ᴀssume is Charles Xavier. Patrick Stewart’s appearance in the cast lineup then hinted that Avengers: Doomsday would spotlight cast from Fox’s X-Men franchise, which subsequent reveals confirmed.

The arrival of such actors as Ian McKellen and Alan Cumming supports one incredibly convincing theory: that the MCU’s foremost stars will be joined by the X-Men cast from an alternate universe. This stands to reason, given that the only places that the likes of Patrick Stewart and Kelsey Grammer have appeared in the MCU thus far have been alternate, even parallel, universes. It also all but confirms that the multiverse, which has been conspicuously neglected in much of the Multiverse Saga’s installments, will play a key role in Avengers: Doomsday and probably Avengers: Secret Wars.

Captain America: Brave New World’s Post-Credits Scene Teased A Fight Against “Others”

He Refers To The Others As “Heroes”

The upcoming focus on alternate universes was teased in the post-credits scene for Captain America: Brave New World. This scene saw Sam Wilson visiting Samuel Sterns on the Raft, ostensibly to gloat about winning their previous bet. He left, however, with knowledge of an impending threat, as Sterns said to Captain America:

“It’s coming. I’ve seen it in the probabilities, seen it plain as day. All you heroes, protecting this world — do you think you’re the only ones? Do you think this is the only world? We’ll see what happens when you have to protect this place from the others.”

Sterns’ mention of other worlds needs little elaboration after alternate universes were established in such installments as Doctor Strange in the Multiverse of Madness and Loki. At the same time, outside of Doctor Strange’s encounter with the concept of Incursions, this is the first time that the MCU’s leading cast has been explicitly informed of a looming threat from another universe. Given that the arch-villain of the Multiverse Saga, Doctor Doom, was only announced less than a year ago, it stands to reason that Doom would be at the helm of such an invasion.

This raises an interesting question, as Sterns specifically references other “Heroes,” whereas Doom is traditionally an outright villain. Rumors swirling about the return of other legacy MCU actors like Chris Evans therefore lends credence to the theory that Robert Downey Jr and his The Avengers co-stars would be portraying dark reflections of their Earth-616 counterparts – namely, the Dark Avengers. This would help to explain Robert Downey Jr.’s casting after portraying the character most synonymous with the MCU.

An alternative theory, of course, is that Sterns is referring to another group of more cut-and-dry heroes. With Doctor Doom traditionally being a lone wolf and Chris Evans continuing to flout reports of his return to the MCU, this one feels even more convincing. Nevertheless, the specific idenтιтy of this group of heroes remained a mystery until Marvel’s surprise announcement. Now, I think it’s obvious who the “others” to whom Sterns referred are.

The Leader Was Warning Captain America About Fox’s X-Men

The Avengers: Doomsday Live Stream Reveals Exactly Which Superhero Team The Avengers Will Face

The Avengers: Doomsday start of production announcement stopped short of revealing which characters each actor would be playing. Nevertheless, with the unmistakable sound of the theme tune from X-Men: The Animated Series accompanying Patrick Stewart’s reveal, it is now undeniably the case that the characters from Fox’s X-Men franchise will star alongside the MCU’s main cast in Avengers: Doomsday. This feels somewhat necessary to establish given how Robert Downey Jr. himself is an example of how the multiverse stipulates the same actor can portray different characters.

This, combined with the Leader’s foreboding words, suggests that Avengers: Doomsday will pit the Avengers against the X-Men in an adaptation of the same event that pervades Marvel Comics. I’m hopeful that there will be more X-Men en route for the official Avengers: Doomsday cast, as notable absentees include Storm and Jean Grey, whose involvement will be anticipated and provide some compelling stories and fights for the Multiverse Saga’s climactic movie to adapt.

What The Leader’s Warning Means For Avengers: Doomsday

It Looks Like Avengers: Doomsday Will Be Avengers Vs. X-Men

While the Leader’s comments certainly suggest that the X-Men and Avengers will be locking horns in Avengers: Doomsday, this raises a particularly pertinent question about the surrounding circumstances. Both groups are composed of superheroes, and it would take an exceptional reason for these two virtuous teams to turn their sights on one another. There is a comic book precedent for such a showdown, but these typically comprise a Civil War style of conflicting interests.

With that in mind, it seems likely that the two groups will clash as an incursion threatens both of their universes. Given an incursion can threaten the fate of both universes, this should amount to a fight for survival, bringing some heartbreaking stakes as two beloved groups of superheroes go toe-to-toe. Furthermore, the collective age of the X-Men cast gives us a pretty big hint that this cohort will not make it out unscathed, particularly with Earth-616 housing so many characters still in the infancy of their respective franchises.

Then again, it’s worth thinking about how Doctor Doom fits into all of this. With a name like Avengers: Doomsday, it seems likely that the Avengers and X-Men will ultimately rally together against Doctor Doom and whatever designs he has planned for the movie. Still, the Leader’s warning did not mention Doctor Doom, so I would imagine that a fight will break out between the two groups of heroes before they join up, and I don’t think I’m ready for the emotional impact.

Upcoming MCU Movies

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  Thunderbolts*

  Release Date

  
  May 2, 2025
  

  
  
  
  

  
  

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  The Fantastic Four: First Steps

  Release Date

  
  July 25, 2025
  

  
  
  
  

  
  

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  Avengers: Doomsday (2026)

  
  
  
  
  

  
  

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  Spider-Man: Brand New Day

  Release Date

  
  July 31, 2026
  

  
  
  
  

  
  

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  Avengers: Secret Wars

  Release Date

  
  May 7, 2027
  

  
  
  
  

  
  

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