Robert Downey Jr. Says Playing Doctor Doom Left Him Feeling "Isolated" From His Former Avengers Co-Stars: "It Was Really Weird"

When Robert Downey Jr. shocked Hall H with his return to the Marvel Cinematic Universe as Victor Von Doom, you may have wondered what it would be like for him step back into the MCU as the villain. Well, it turns out it was a strange experience for Downey.

Following Marvel Studios' Hall H presentation at San Diego Comic-Con 2026, where fans got another look at Avengers: Doomsday, Downey opened up about making the jump from beloved hero Tony Stark to one of Marvel's most dangerous villains.

While speaking with Entertainment Weekly, he talked about the similarities and differences between Iron Man and Doctor Doom, explaining:

"I mean there's the science thing and they're considered pretty brilliant guys but Tony had the trauma that turned him into a hero and Doom has got the exact opposite to where it takes the prowess of all of these folks to go up against him.

“It was a joy to pull [off]. It was really weird being on the other side of a bad guy mask because it's just such an isolated vibe, and I'm seeing them all socialize and I'm the enemy."

That's got to be an unusual adjustment after spending more than a decade as the heart of the Avengers. Instead of hanging out with Earth's Mightiest Heroes between takes, Downey suddenly found himself watching his longtime friends from the opposite side of the battlefield.

It's a fun reminder that even though everyone knows it's make-believe, stepping into a villain's shoes can completely change the dynamic on set.

Downey wasn't the only one reflecting on the reunion. Chris Evans, who returns as Steve Rogers in Avengers: Doomsday, admitted being back with the original cast brought back memories of making the first Avengers movie.

Evans said: "I would find myself during that movie watching. You're in the scene but then you're like, 'Robert Downey Jr.'s playing Tony Stark' and 'Oh f*ck, I have a line,.’ And on this one I felt that a little bit again, just kind of watching you do this thing that I couldn't wait to see."

That reunion factor is shaping up to be one of the movie's biggest draws. Seeing Downey and Evans sharing scenes again is exciting on its own, but flipping their roles so that Captain America is standing against Doctor Doom instead of alongside Iron Man adds a whole new layer to the story.

Avengers: Doomsday is bringing together one of the biggest ensembles Marvel has ever assembled. Along with returning Avengers like Thor and Steve Rogers, the film also features characters from Thunderbolts, Black Panther, The Fantastic Four, and even the Fox X-Men movies.

Marvel is still keeping most of the story under wraps. The official synopsis simply reads: "Universes collide and the Multiverse Saga begins its final chapter in Marvel Studios' Avengers: Doomsday.

“Beloved heroes from three distinct universes will be set on a deadly collision course and ultimately face an existential threat unlike anything they've ever encountered. This epic film will lay the foundation for the future of the Marvel Cinematic Universe."

Fans also got a taste of the massive scale during the new Avengers: Doomsday trailer shown at Comic-Con, teasing the kind of multiversal chaos you'd expect when Doctor Doom is at the center of the conflict.

We'll finally see how Downey's take on Victor Von Doom reshapes the MCU when Avengers: Doomsday arrives in theaters on December 18, 2026.