Avengers Doomsday: All 8 Marvel Villains Reported to Appear

Marvel Studios' Avengers: Doomsday will be jam-packed with villains, but the real question is which of them will be evil. Doomsday is already confirmed to feature arguably the biggest cast of actors in comic book movie history, complete with multiple generations of stars from the last 30 years. Naturally, this cast will make up the fight between good and evil, with multiple villains making their return to the Marvel universe.

Eight current and former Marvel villains will play roles in the MCU's Avengers: Doomsday. This movie will deliver the crossover event of all crossover events, courtesy of over two dozen heroes from about half a dozen different franchises joining forces to protect the multiverse. However, outside of one major villainous name, a handful of legacy antagonists may add to the chaos in this story.

Villains Who Will Definitely Be Evil in Doomsday

Doctor Doom

As of writing, the only character guaranteed to star in Avengers: Doomsday as a villain is the character who inspires the movie's subtitle: Victor von Doom. Previously played by the late Julian McMahon and Toby Kebbell, Marvel Studios will fill this role with Robert Downey Jr., best known for leading the Infinity Saga as Tony Stark/Iron Man from 2008 to 2019.

While details about this film's plot still remain unknown, rumors tease that Downey's Doom will have some sort of vendetta against the multiverse, leading to his quest to tear it all down. Even with other antagonists potentially in play here, nobody will have the same impact as Downey when he goes up against the MCU's best.

Villains Who Might Be Evil in Doomsday

Magneto

Included in Marvel Studios' Doomsday cast announcement from March 2025, Sir Ian McKellen was confirmed to return to his iconic role as Erik Lehnsherr/Magneto. McKellen starred in the original X-Men trilogy as the Omega-level mutant and made appearances in five total movies, his last Marvel credit coming in 2014's X-Men: Days of Future Past.

Magneto's allegiances have always operated in a grey area. He is a lifelong friend of Professor X but believes wholeheartedly in mutant supremacy and will do anything to make that a reality. While both Erik and Charles are part of this story, Doom could realistically convince Magneto to join his side and give him plenty of extra firepower.

Mystique

One of Doomsday's more shocking casting announcements included Rebecca Romijn, known in the Marvel Universe for playing Raven Darkhölme/Mystique. Mystique, known for her shapeshifting abilities, was integral to the original three X-Men films, and Romijn also had a quick cameo in 2011's X-Men: First Class.

Mystique's allegiances have fluctuated over the years, as she has worked closely with both Charles Xavier and Erik Lehnsherr on multiple occasions. While she will most likely be utilized as a hero in Doomsday, she may look out for her own interests if Magneto winds up defecting to Doom's side.

Loki 

Tom Hiddleston's Loki will be a pivotal figure in Avengers: Doomsday when he makes his Phase 6 debut. Having played the God of Mischief (who later became the God of Stories) since 2011's Thor, Hiddleston will join his 10th MCU project when he plays the Asgardian hero again in 2026. 

Hiddleston's Loki is at the end of his redemption arc, sitting on a throne and holding the entire Sacred Timeline together after helping save the entire multiverse. However, given his villainous past and the chance of multiple Loki variants coming into play, the MCU veteran could potentially show his villainous side again alongside another longtime MCU fan-favorite in Robert Downey Jr.

Villains Who Will Be Heroes in Doomsday

Ghost

Hannah John-Kamen joined the MCU in 2018's Ant-Man and the Wasp as the villainous Ava Starr/Ghost, who hoped to capture Janet Van Dyne to help her solve her molecular disequilibrium problem. After getting that issue fixed, she returned in 2025's Thunderbolts*, initially working under Valentina Allegra de Fontaine before joining the rest of the Thunderbolts team and becoming a hero.

John-Kamen's Ava now operates in a more positive light, working as part of the New Avengers after the team was announced to the world at the end of Thunderbolts*. Known for her phasing abilities and fighting skills, the former villain now gets to fight for something bigger as she and the rest of her teammates meet up with the Avengers and fight against Doom.

US Agent

Wyatt Russell has toed the line between hero and villain since his introduction as John Walker in The Falcon and the Winter Soldier. Initially introduced as the new man behind the Captain America mantle, Walker moved on to operating as the U.S. Agent under Val, which he continued to do in Thunderbolts*.

After a major change of heart and a few adventures, Walker reformed himself into a hero and joined forces with the New Avengers ahead of Avengers: Doomsday. Putting his villainous past behind him, he will be a key hero in the fight against Doom when he comes back in the next Avengers movie.

Sentry

Lewis Pullman joined the MCU as one of the most powerful characters in Marvel history, playing the role of Robert Reynolds/Sentry in 2025's Thunderbolts*. Dealing with multiple alter-egos, including the evil entity known as The Void, Sentry was made into a powerful hero who can fly and has superstrength, giving the Thunderbolts plenty of issues in the Phase 5 team-up movie.

While Reynolds is currently doing his best to keep the Sentry and the Void under control, he hopes to move past his villain phase so that he can work with the New Avengers as a hero. Doom is sure to look for any way possible to bring that darkness out of Pullman's hero, which could lead to plenty of drama from his side of the fight.

Namor

Namor the Sub-Mariner joined the MCU's ranks of villains in 2022's Black Panther: Wakanda Forever, serving as the leader of the underwater nation of Talokan. Known for his water-based abilities and flight capabilities, along with his ability to command and control ocean life, Namor proved to be a powerful adversary before coming to a truce with Shuri and halting his assault on Wakanda.

Tenoch Huerta's Talokan leader is expected to be an ally for the Black Panther and the Wakandans as they help protect the world from Doom. While his story in this movie is still unknown, this former villain will not be somebody to trifle with as he shows his protective nature.

Avengers: Doomsday will be the MCU's fifth Avengers movie and the first since 2019's Avengers: Endgame. Featuring a massive cast of over two dozen Marvel stars, generations of heroes will team up to take down Robert Downey Jr.'s Doctor Doom in his quest to destroy the multiverse. Avengers: Doomsday is expected to debut in theaters on December 18, 2026.