What’s It Like Working With Robert Downey Jr. On Avengers: Doomsday? Simu Liu Shares A Sweet Take

As we look forward to the release of Avengers: Doomsday among the upcoming Marvel movies on the way, anticipation is high for the return of Robert Downey Jr., this time as the villain, Doctor Doom. While we know full well the cast isn’t going to tell journalists much of anything about what’s going on set as the movie continues to go through production, Shang-Chi actor Simu Liu did have some sweet words to share about getting to work with the former Iron Man actor.

Simu Liu was asked about filming Avengers: Doomsday for the Japanese publication The River (with his words translated from Japanese in the article). RDJ’s name came up when Liu was asked which cast member has inspired him the most on the set. He shared:

Robert Downey Jr., of course, effectively helped launch the MCU with his role in Iron Man, and was really the life blood of the superhero franchise across numerous films over the years. Liu also said that “every day feels like a dream” working on the Avengers project after debuting into the universe in 2021 with Shang-Chi And The Legend of the Ten Rings. Liu said he can hardly believe he’s working with the cast of Avengers: Doomsday, which was revealed to the public through a five-hour livestream. As he continued about Downey Jr.:

Robert Downey Jr. surprised Hall H during San Diego Comic-Con in 2024 with the announcement that he’d be back in the MCU, but as Doctor Doom rather than Tony Stark. Since then, there was a tease at the end of Fantastic Four: First Steps that points to Doctor Doom’s reign of terror perhaps having something to do with the son of Reed Richards and Sue Storm, but there’s still a lot we have left to learn about the plot of Avengers: Doomsday.

Simu Liu is in the Doomsday cast that is full to the brim with star power. From Chris Hemsworth coming back as Thor, Paul Rudd as Ant-Man, Letitia Wright as Black Panther, to some of the original X-Men, including Patrick Stewart and Ian McKellen playing their mutant roles again, to the Thunderbolts/New Avengers and Fantastic Four, it must be incredibly overwhelming. Liu told the publication that while he’s been feeling “anxious at times” on the set, his cast-mates are “so wonderful” that it doesn’t even feel like work.

There’s already a lot of fan theories out there about what the next Avengers movies could mean for the MCU, but we’ll have to wait to see it all come together on December 18, 2026.