The MCU's Most Ambitious Crossover Before Avengers: Doomsday Comes Out In 3 Months

Avengers: Doomsday is primed to be the biggest Marvel crossover movie of all time, but before it premieres, the MCU's most ambitious film to date is being released in just three months. The cast of Avengers: Doomsday will feature a huge number of prominent Marvel superheroes ranging from Thor to Shang-Chi to the Fantastic Four. There are also plenty of other MCU characters rumored to be in Doomsday, such as Ms. Marvel, though they haven't been officially confirmed.

Avengers: Doomsday isn't just reuniting the main MCU, though, it's also expanding. Several actors from Fox's X-Men movies, including Patrick Stewart as Charles Xavier, James Marsden as Cyclops, and many more, are reprising their roles for Doomsday. The film has also brought back Chris Evans as Steve Rogers despite his storyline in Avengers: Endgame, while Robert Downey Jr. will be portraying Doctor Doom instead of Tony Stark.

Based on the casting news that's officially available, it's safe to say that Avengers: Doomsday will be the MCU's biggest crossover event ever. Before it premieres in theaters on December 18, however, another MCU movie, Spider-Man: Brand New Day, could briefly be the most ambitious team-up to date. Though it's primarily focused on Tom Holland's Peter Parker, and won't feature nearly as many characters as Doomsday, Spider-Man: Brand New Day could unite the various Marvel franchises even sooner.

Spider-Man: Brand New Day Could Unite The Avengers, Defenders, & X-Men

The cast of Spider-Man: Brand New Day already has quite a few crossovers set up for the upcoming film. Both the Punisher and the Hulk are prominently featured in the trailers for Brand New Day, and they serve as bridges between the films and their respective franchises. The Hulk, for example, acts as a crossover between Spider-Man and the Avengers, while the Punisher is a crossover with Netflix's street-level heroes, the franchise including Daredevil, Jessica Jones, and the Defenders.

Hulk and the Punisher alone make Spider-Man: Brand New Day a fairly ambitious crossover event, but No Way Home also included representatives of both their franchises in Doctor Strange and Daredevil. What could truly make Brand New Day groundbreaking is another actor: Sadie Sink. Though Sink is confirmed to appear in the film, her role still hasn't been officially revealed. That has led to quite a bit of speculation, and the prevailing theory presents a huge opportunity.

Many MCU fans believe Sadie Sink could play Jean Grey in Spider-Man: Brand New Day. Jean, of course, is a prominent psychic and a major member of the X-Men, though the character was played most prominently by Famke Janssen and Sophie Turner in Fox's X-Men movies. If Sink does end up playing Jean Grey, it would make Spider-Man: Brand New Day the first MCU film to include heroes from all three major franchises: the Avengers, the Defenders, and the X-Men.

Other X-Men characters have appeared in the MCU before, such as Wolverine in Deadpool & Wolverine, but that film didn't have any of the main members of the Avengers or Defenders in it. Spider-Man: Brand New Day can't compete with the sheer number of heroes in Avengers: Doomsday, but if Sadie Sink is playing Jean Grey, it will beat Doomsday to the punch of uniting the three major Marvel franchises in the same movie.

Spider-Man: Brand New Day Could Show How The MCU Will Handle The X-Men

If Sadie Sink is playing Jean Grey, then Spider-Man: Brand New Day could be a litmus test to see how the MCU will handle the X-Men as a whole several months before Avengers: Doomsday. So far, the MCU has had a few different takes on mutant characters. The Scarlet Witch and Quicksilver, for example, had their origins changed in Avengers: Age of Ultron. Other projects, like Doctor Strange in the Multiverse of Madness and Deadpool & Wolverine, featured variants of Professor X and Wolverine from alternate realities.

Spider-Man: Brand New Day has a chance to define how the mainline MCU is going to handle the sudden influx of proper mutant heroes. Jean Grey's apparent recasting could be an indicator that the main Marvel universe has its own version of mutants, and that the actors from Fox's X-Men will be from a new universe in the multiverse. Conversely, Jean Grey could potentially be explained as also being from another universe and coming to the main MCU universe.

The movie will also be a chance to see if the MCU can do these characters justice. Fox's X-Men films had their ups and downs, and the MCU has also handled some characters with more grace and comic book accuracy than others. It remains to be seen if X-Men characters like Jean Grey will live up to the legacy of their characters as they make their debut in the MCU. Spider-Man: Brand New Day has a chance to prove that the franchise is up to the task even before Avengers: Doomsday does.