Doomsday and Secret Wars are expected to feature battles on a scale even greater than Infinity War and Endgame, and the Avengers alone won't be enough to face a formidable villain like Doctor Doom.

The Multiverse Saga of Marvel Studios is nearing its conclusion, with two massive Avengers films, Avengers: Doomsday and Avengers: Secret Wars, scheduled for release in 2026 and 2027. These films are set to be the largest projects in the MCU's history, possibly even bigger than Infinity War and Endgame. As a result, it's no surprise that the final multiversal battle will bring together various superhero teams, along with the return of the Avengers after years of inactivity.
Avengers & Guardians of the Galaxy will return to the big screen in Doomsday and Secret Wars

Avengers and Guardians of the Galaxy had an unexpected collaboration during Infinity War and Endgame - Image: Internet.
The Avengers will play a central role in the conclusion of the Multiverse Saga, marking their long-awaited return after the team had gone inactive following Endgame. The team's roster has undergone significant changes, with core members like Iron Man, Captain America (Steve Rogers), and Black Widow having left.
Instead, the new Avengers team will likely be led by seasoned heroes such as Doctor Strange, Captain Marvel, Wong, Hulk, Thor, Sam Wilson (the new Captain America), and Spider-Man, who has had his own multiversal experiences in No Way Home. Additionally, the new Avengers lineup will include promising characters like Shang-Chi, the new wielder of the Ten Rings, and powerful Eternals.
The Guardians of the Galaxy are also expected to return in Secret Wars, especially considering their significant role in Infinity War and Endgame. Similar to the Avengers, the Guardians have undergone numerous changes, now led by Rocket Raccoon. The new team includes Groot, Adam Warlock, Phyla, Kraglin, and Cosmo the dog. Additionally, Peter Quill, aka Star-Lord, will also return to the MCU in a solo project, making it hard to imagine him missing out on such a major event as Secret Wars.
Young Avengers & Thunderbolts

Both Thunderbolts and Young Avengers are actively being developed within the MCU – Image: Internet.
Young Avengers and Thunderbolts are seen as the next generation of superheroes to follow in the footsteps of the Avengers within the MCU. While Thunderbolts is set to be explored in its own film release on May 2, Young Avengers has been gradually assembling over the years with several promising members who could rival the original Avengers team.
In a post-credit scene of The Marvels, Kamala Khan/Ms. Marvel directly recruits Kate Bishop for a new superhero team, which is believed to be the Young Avengers. The team will also include Cassie Lang – daughter of Ant-Man, America Chavez – a hero with the ability to travel between parallel universes, and Ironheart – a genius inventor of advanced suits similar to Tony Stark's, despite limited resources and finances. Additionally, Billy Maximoff/Billy Kaplan, the son of Wanda Maximoff, is expected to join the team in the future.
Meanwhile, Thunderbolts will make its official MCU debut this May through the blockbuster Thunderbolts*. The asterisk in the film’s title suggests that this could be a placeholder name, and some fans speculate that this might serve as the foundation for bringing the Dark Avengers to the big screen. The current members of Thunderbolts will include Yelena Belova, James Bucky Barnes (Winter Soldier), John Walker (US Agent), Alexei Shostakov (Red Guardian), Ava Starr (Ghost), Antonia Dreykov (Taskmaster), and Valentina Allegra de Fontaine.
Fantastic Four & X-Men

Fantastic Four and X-Men are seen as the future of the MCU following the Multiverse Saga – Image: Internet.
Alongside the Avengers, the Fantastic Four is the second confirmed superhero team to appear in Secret Wars. Marvel's first family will officially make their MCU debut in the upcoming blockbuster The Fantastic Four: First Steps, slated for release on July 25 this year. This film will take place in an alternate universe and feature two major villains, Galactus and Doctor Doom. As Doom is set to be the 'final boss' of the Multiverse Saga, it's no surprise that the Fantastic Four will play a crucial role in both Doomsday and Secret Wars.
Meanwhile, the X-Men are likely to be explored more deeply after the conclusion of the Multiverse Saga. However, Marvel Studios has already teased several mutants within the MCU, particularly those from Fox's former cinematic universe. Besides Deadpool and Wolverine, audiences have also seen Charles Xavier/Professor X in Doctor Strange in the Multiverse of Madness and Beast in Ms. Marvel. The multiversal battle in Secret Wars offers an excellent opportunity for these iconic heroes to return to the big screen and bid farewell to Fox's X-Men universe, paving the way for Marvel's new version of the mutants.
The Defenders

The Defenders will join the MCU in Daredevil: Born Again – Image: Internet.
The new trailer for Daredevil: Born Again has confirmed the return of several familiar faces from the Netflix Defenders universe to the MCU, including Matt Murdock, Wilson Fisk/Kingpin, and Frank Castle/Punisher. As Daredevil: Born Again connects with the previous Netflix series, it's likely that other Defenders superheroes, such as Jessica Jones, Luke Cage, and Iron Fist, will also make an appearance in the project.
The Defenders typically operate on a smaller scale than the Avengers and are often regarded as street-level superheroes. However, given the chaos within the multiverse and Spider-Man's previous involvement in large-scale battles, it's possible that Daredevil and his allies will join forces with the Avengers to fight against Doom in Secret Wars.
Midnight Sons

There have been several clues pointing to the Midnight Sons team within the MCU – Image: Internet.
Since the events of Endgame, Marvel Studios has increasingly explored mystical and magical elements through projects like Doctor Strange, Werewolf by Night, and Moon Knight. This has led many fans to believe that Marvel is quietly assembling a new team to tackle supernatural threats in the MCU – the Midnight Sons. This team consists of characters like Doctor Strange, Blade, Elsa Bloodstone, Wong, Moon Knight, and Man-Thing, all of whom are either currently in or will be appearing in the Marvel Cinematic Universe.
Doctor Strange is considered one of the central figures of the Multiverse Saga and plays a crucial role in the upcoming Avengers films. Therefore, there is a small possibility that he might gather the Midnight Sons before the events of Secret Wars, leading both of his superhero teams into battle against Doctor Doom.
Source: ScreenRant