Avengers: Doomsday is set to include the X-Men, and I am convinced that the mutants will aid the film in replicating something that Avengers: Infinity War and Avengers: Endgame work so well. The story of Avengers: Doomsday, on a broad level, will focus on several teams from across the MCU multiverse battling against Robert Downey Jr. as Doctor Doom. In March 2025, Marvel Studios unveiled the actors – and thus, the heroes – that will be part of Avengers: Doomsday‘s cast list.

The likes of Anthony Mackie, Danny Ramirez, Chris Hemsworth, Simu Liu, and Paul Rudd will make up the core Avengers team of the upcoming Marvel movie, alongside their Wakandan allies, played by Leтιтia Wright and Winston Duke. The last two Marvel movies of 2025 then introduced the other two teams – the New Avengers and The Fantastic Four. Another, which was more shocking, was the X-Men, confirmed to be part of Avengers: Doomsday via the MCU multiverse and seeing the return of iconic actors from the Fox movies. Thanks to this inclusion, the film can copy a vital trick from the previous two Avengers films.

Avengers: Infinity War & Avengers: Endgame Worked Excellently As A Culmination Of The Infinity Saga

Thanks To The Emotional Investment In The MCU’s Characters

Firstly, it is worth exploring what made Avengers: Infinity War and Avengers: Endgame so worthy as a conclusion to the Infinity Saga. The primary reason was the years of investment audiences already had in the MCU’s characters. The three main heroes of the franchise – Iron Man, Captain America, and Thor – had appeared in three movies each, while the likes of Hulk, Black Widow, and Hawkeye had major supporting roles across 11 years of movies. Then there were characters like the Guardians of the Galaxy who had two movies of their own.

There had also been two Avengers movies, three if you wanted to count Captain America: Civil War, that fleshed out the dynamic of the team so well. The first of these, 2012’s The Avengers, teased Thanos for the first time, meaning he was set up over six years of storytelling and linked multiple franchises together by also appearing in the Guardians movies. All of this allowed the core members of the Infinity Saga to be well-fleshed-out, in-depth characters with arcs that were building to a natural conclusion: the two Avengers movies of 2018 and 2019.

Avengers: Doomsday & Avengers: Secret Wars’ Do Not Have The Same Strength In Depth

The Multiverse Saga Has Been Much More Scattered

Unfortunately, Avengers: Doomsday and Avengers: Secret Wars have not been built up as efficiently as Infinity War and Endgame were. The core trinity of characters is now mostly gone, and Thor has only had one appearance in the Multiverse Saga with Thor: Love and Thunder, a film that was not well-received by fans. Captain America has only had one movie that established his role in the MCU, which, similarly, was not considered a worthy story for what his character deserves.

Then there are the likes of Shang-Chi, the Thunderbolts/New Avengers, and The Fantastic Four who, at the time of Avengers: Doomsday‘s release, will have only had one MCU appearance each. Some of the Thunderbolts members have appeared in numerous films, but many would agree they work better as a team – a team that will only have had one appearance together in December 2026. Finally, the villain of Avengers: Doomsday and Avengers: Secret Wars is much more of an unknown quanтιтy than Thanos was in the Infinity Saga.

I will not claim that Thanos had an extensive background or catalog of MCU appearances before Avengers: Infinity War, but it was at least clear that he was being teased as the main villain the Avengers would eventually face when the franchise’s story came to a head. This allowed his appearance in Avengers: Infinity War to have more weight, whereas Avengers: Doomsday will be Doctor Doom’s debut in the franchise. For this reason, the upcoming Avengers movies are somewhat lacking in build-up in a way the previous two were not.

The X-Men Provide Avengers: Doomsday With Several Movies Worth Of Emotional Investment

A Wildcard Is Part Of Avengers: Doomsday

All that being said, the inclusion of the X-Men in Avengers: Doomsday could provide the film with the emotional punch it needs. I would like to point out that I think Doomsday can work without the aforementioned build-up I have outlined, but it remains true that the Multiverse Saga has not had a similar defined, compelling, core group of characters that the Infinity Saga had to be invested in. Nonetheless, the X-Men could provide this group.

It is unclear which versions of the X-Men will appear in Avengers: Doomsday, but the cast announcement for the film at least confirmed that the same actors from the Fox X-Men movie timeline will return. Seeing the likes of Patrick Stewart, Ian McKellen, Kelsey Grammer, and James Marsden back as their characters from two decades ago will subconsciously cause audiences to be invested in the team, even if they are playing different variants.

These characters all appeared in the original X-Men trilogy, two of which were beloved films. Many then reprised their roles in X-Men: Days of Future Past, which is widely considered the best movie in the franchise. While the X-Men timeline became confusing after this point, none can deny the emotional investment audiences had in these actors as these characters. Therefore, Avengers: Doomsday can capitalize on this and bump up the emotional weight of the film by drawing on the history of the X-Men.