Robert Downey Jr. will always be an integral part of the Marvel Cinematic Universe thanks to his portrayal as Tony Stark / Iron Man. Downey kicked off the MCU with Iron Man all the way back in 2008 and helped build it into the blockbuster franchise it has become in the near-two decades since. Now he’s taking on a new role as Doctor Doom in Avengers: Doomsday.
Whether he, as Doom, will make the same impression on fans as he did as Iron Man remains to be seen. But one of Downey’s Doomsday costars seems to think he will.
Simu Liu thinks Robert Downey Jr.’s Doctor Doom will impress fans
Simu Liu, who will reprise his role as Shang-Chi in the upcoming Avengers movie, recently did an exclusive interview with the Japanese media outlet The River. During the conversation, Liu mentioned that there wasn’t a lot he could say about Avengers: Doomsday. But the little he did reveal about filming the movie included rave reviews of Robert Downey Jr.'s performance as Doctor Doom.
“I think everyone will be blown away by the way he tackles this new character (Doctor Doom) in this film,” Liu said.
There’s no word on how Liu’s Shang-Chi will fit into Avengers: Doomsday or what kind of interactions he’ll have with Downey’s Doom — if any. Shang-Chi was last seen in live action in his MCU debut of Shang-Chi and the Legend of the Ten Rings back in 2021. In the film’s post-credits scene, Wong brought Shang-Chi and Awkafina’s Katy through a portal, where they also met (holographs of) Carol Danvers / Captain Marvel and Bruce Banner. The group discussed the Ten Rings and their origin.
That scene has, understandably, yet to be addressed, so it’s possible Marvel will try to use that to tie that into Doomsday. That could then bring Shang-Chi into a larger narrative that justifies him interacting with other heroes, like Anthony Mackie’s Sam Wilson / Captain America — who was announced as part of the Doomsday cast in the same live stream alongside Liu and others.
Earlier this year, Liu joined Downey, Mackie, and other Doomsday costars for a screening of Thunderbolts*. The starring cast for Doomsday is extensive and rumored to become even bigger, but the movie night group could be telling of which characters Liu’s Shang-Chi will be working with primarily.
Liu spoke fondly of Downey beyond his acting skills, though. Beyond the Doom tease, he praised the MCU veteran for being an A-lister who can be admired as a person.
"He's been an integral part of Marvel's success and has been in so many films over the years, yet he still takes the time to meet and connect with so many people. He's such a kind, generous, and inspiring person."
Avengers: Doomsday is scheduled for theatrical release on Dec. 18, 2026.