Summary
- RDJ's return as Doctor Doom could involve his mind taking over Iron Man's dead body, connecting to the Fantastic Four reboot.
- Marvel had considered resurrecting RDJ's Tony Stark for a possible original Avengers reunion movie.
- RDJ's casting as Doctor Doom injects excitement into the MCU, bringing back the franchise's most beloved star.
A new MCU movies made the return even more surprising. Marvel did not explain how RDJ could play Doctor Doom.
Downey became popular in the MCU for giving life to Tony Stark. After Iron Man's sacrifice in Avengers: Endgame, it seemed like Downey had moved on from Marvel, pursuing different kinds of films, which led to the star winning Best ing Actor for Oppenheimer at the Oscars and many more awards. With the multiverse, anything is possible, so Downey's Doctor Doom might not come from Earth-616, the same as his Iron Man, but another universe. However, a dark MCU theory offers a more complex twist to the reason RDJ was cast as Doom, setting up Avengers: Doomsday's story.
10 Reasons Robert Downey Jr. Is Perfect For The MCU’s Doctor Doom
Robert Downey Jr. is leaving Iron Man to play the MCU's Doctor Doom, which has led to differing opinions, but the casting works for a few key reasons.
MCU Theory: Doctor Doom’s Mind Takes Over Iron Man’s Dead Body
RDJ Returns As Tony Stark In A Way
There is a way for RDJ to return to the MCU as both Doctor Doom and Iron Man in one single role. According to a theory shared on Reddit by Robert Downey Jr.'s Doctor Doom is in The Fantastic Four: First Steps, making his debut in the movie's mid/post-credits scene. The theory proposes that while RDJ's Doom will appear in the credits scene, another actor will be playing Doom in the movie itself.
With Galactus as the Fantastic Four reboot villain and the team having to go to Earth-616, the theory claims Galactus devours the Fantastic Four's Earth, with Doom forced to find a way to survive. The villain would then use a machine similar to the one he used to confront Mephisto in Marvel Comics, with his consciousness traveling the multiverse and landing on Tony Stark's dead body, with Iron Man's use of the Infinity Stones leaving a beacon for Doom. In the comics, Doom once transferred his consciousness into a dead Wolverine — though he transplanted his brain — which sets a precedent.
What RDJ's Doctor Doom Casting Means For Iron Man's MCU Return Theories
Robert Downey Jr. is coming back to the Marvel Cinematic Universe to play Doctor Doom, and that casting impacts Iron Man's return chances directly.
Marvel Studios Was Reportedly Considering To Resurrect RDJ’s Tony Stark
Marvel Has Been Looking Over Its Multiverse Saga Plans
The dark MCU theory for RDJ's Doctor Doom connects to a past report about a possible Iron Man return. In November 2023, a report claimed that Marvel was considering a new Avengers movie with the original cast, meaning RDJ, Chris Evans, Chris Hemsworth, Mark Ruffalo, Jeremy Renner, and Scarlett Johansson would all return as their MCU heroes. Talks about the possible original Avengers reunion had started due to the MCU's many issues in Phase 4, which stands as the franchise's most criticized by far. The only problem with that idea is that two characters are dead.
However, according to the report, Marvel would resurrect RDJ's Iron Man and Johansson's Black Widow for the original Avengers' reunion movie. At the time, it seemed like the report was talking about a traditional Avengers movie with the original crew back together; however, given Downey Jr.'s casting as Doctor Doom, it seems like that idea might have evolved into something else. RDJ's Doom might not be the only twist to the original Avengers, with 2026's Avengers: Doomsday possibly bringing back more of the original Avengers cast as different Marvel villains with a multiverse twist to them.
What Every Original Avenger Actor Has Said About Returning In Future MCU Movies
Considering they played such a pivotal role in the MCU, there's great interest in the return of the original Avengers actors to the franchise.
How RDJ As Doctor Doom Could Be The MCU’s Best Move
The Casting Injects Excitement Into The Franchise
RDJ's casting as Doctor Doom has many fans excited about the future of the MCU, and for good reason. While a traditional Doom would have been great to see, having the MCU's most beloved actor return to the franchise with a twist as perhaps Marvel Comics' best villain is a fantastic alternative. After Jonathan Majors was fired from the MCU, Downey's casting as Doctor Doom was the easiest way for Marvel to get audiences to forget about Kang the Conqueror, as the excitement about Downey's return and the many questions around the casting took up the conversation.
Adding to that, RDJ's recent Oscar win in an antagonist role, as well as his long career, show he has the acting skills to bring such a complex villain like Doctor Doom to life masterfully. Downey also has a past with the character, as the actor had talks to play Doctor Doom in the 2000s Fantastic Four movies before ultimately playing Iron Man in the MCU. Finally, RDJ being the face behind Doctor Doom's mask should lead to some heartbreaking moments as the Avengers discover the villain looks just like Tony Stark — or is him like the MCU theory suggests.
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The Fantastic Four: First Steps
- Release Date
- July 25, 2025
- Director
- Matt Shakman
- Writers
- Jeff Kaplan, Josh Friedman, Ian Springer, Eric Pearson, Stan Lee
- Producers
- Jamie Christopher, Kevin Feige, Louis D'Esposito, Tim Lewis
- Franchise(s)
- Marvel Cinematic Universe
Cast
Reed Richards / Mr. Fantastic
Vanessa KirbySue Storm / The Invisible Woman
Johnny Storm / Human Torch
Ebon Moss-BachrachBen Grimm / The Thing
The Fantastic Four: First Steps depicts Marvel's First Family navigating their roles as heroes amidst a 1960s-inspired, retro-futuristic world. As they defend Earth from Galactus and the enigmatic Silver Surfer, they must also uphold the strength of their family bond.
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Avengers: Doomsday is the fifth Avengers film in the Marvel Cinematic Universe and will bring together heroes, new and old, to face off against Victor von Doom - played by the returning Robert DOwney Jr. Avengers: Doomsday will also mark the beginning of phase 6 of the MCU.
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Avengers: Secret Wars
- Release Date
- December 17, 2027
- Director
- Joe Russo
- Writers
- Stephen McFeely, Stan Lee
- Prequel(s)
- Avengers: Doomsday
- Franchise(s)
- Marvel Cinematic Universe
Cast
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Reed Richards / Mr. Fantastic
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Vanessa KirbySue Storm / Invisible Woman
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Johnny Storm / Human Torch
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Ebon Moss-BachrachBen Grimm / The Thing
Avengers: Secret Wars is the sixth Avengers film and takes place during Phase Six of Marvel's Cinematic Universe.
