Secret Wars would be Avengers 5’s best pay-off for its multiverse story. It’s no secret now that the Marvel Cinematic Universe will tackle the multiverse in Phase Four (and maybe beyond). The idea of multiple worlds existing in the universe was first established in the Disney+ series Loki, which introduced the concept of variants, people who pose a threat to the Sacred Timeline and who are pruned by the Time Variance Authority to prevent it from branching off and creating alternate timelines.
The season 1 finale of Loki introduced He Who Remains — otherwise known as Kang the Conqueror — as the being in charge of keeping the Sacred Timeline in check. The revelation that there once existed a multiverse was shocking to Loki and Sylvie, one of several Loki variants. With the decision made to stab He Who Remains instead of taking his place to maintain the Sacred Timeline, Sylvie unleashed the multiverse once again. Her actions will have repercussions on the entirety of the multiverse, which will likely play out in Doctor Strange in the Multiverse of Madness. The film could lay the groundwork for an all-out Secret Wars storyline for Avengers 5 that would be worthy of the buildup. It’s also an event that would involve multiple superheroes, which would be fitting for a fifth Avengers movie.
Secret Wars is a multiple-issue comic that began in 1984 and saw the Marvel heroes fighting each other on the planet Battleworld. The entire thing was constructed by The Beyonder, a cosmic entity who kidnapped the superheroes (and the villains) from across the multiverse for the ultimate battle royale. The 2015 version of the comic book event saw Marvel’s multiverse combine to create Battleworld. This resulted in different iterations of beloved characters, like Iron Man and Thor, existing in one place that is split into various territories because of the multiversal collision. To that end, Avengers 5 could see all versions of MCU characters from throughout the multiverse duke it out with each other.
The sheer scale of this undertaking would be even greater than Avengers: Endgame and it would be a more satisfying conclusion to the multiverse storyline than the superheroes simply banding together to fight and defeat Kang. Having the superheroes team-up again to battle another cosmic entity would also draw comparisons to their fight with Thanos. Doing Secret Wars would freshen things up while also including the Loki villain and the multiverse at large. It’s long been speculated about how the next Avengers movie could top Avengers: Endgame, but doing a Secret Wars film is the best way to utilize the multiverse (and all that entails) and turn it into a large-scale crossover event within the MCU.
Avengers: Infinity War and Endgame directors Anthony and Joe Russo have been open about their interest in doing a Secret Wars movie in the MCU. They’ve Secret Wars movie. It makes a lot of sense to tackle this massive undertaking to include all the MCU heroes and the multiverse storyline in one fell swoop.
