Avengers: Doomsday is the gift that keeps on giving. Just days after the highly anticipated Marvel movie was confirmed to be in production and its initial 27-strong cast was revealed, fans have come up with two big theories about its plot and the possible return of a popular character.

Fans who spent years watching the Marvel movies in order will remember a popular theory that Ant-Man could kill Thanos by entering his butt and growing. And Paul Rudd trying to explain this to his Death of a Unicorn co-star Jenna Ortega is seriously delightful.

Rebecca Romijn, 52, will officially return as Mystique. She starred as the shapeshifter in “X-Men, X2: X-Men United,” “X-Men: The Last Stand” and “X-Men: First Class and Joan in The Punisher.”

"Avengers: Doomsday" finds brothers Joe and Anthony Russo back in the directors chairs. They return to Marvel having helmed the Captain America films "Captain America: The Winter Soldier" and "Captain America: Civil War," as well as "Avengers: Infinity War" and "Avengers: Endgame."

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SDCC 2024 announced that the Russo brothers will be directing both Avengers: Doomsday and Avengers: Secret Wars. The two are Marvel legends, since they helmed Avengers: Infinity War and Endgame, so it's welcomed news to see their return.

Doomsday' cast was revealed, with Fantastic Four, X-Men and Thunderbolts stars, but few of the original stars.

Chris Hemsworth’s Thor, Anthony Mackie’s Captain America, Sebastian Stan’s Bucky Barnes, Tom Hiddleston's Loki and Paul Rudd’s Ant-Man are all back in the “Avengers” ensemble.