Doctor Doom Takes Over From Iron Man To Become Avengers: Doomsday’s Villain According To MCU Theory

A bold new Marvel Cinematic Universe theory suggests Doctor Doom could take over Iron Man’s role in Avengers: Doomsday – and not just metaphorically. Robert Downey Jr. is returning to the MCU timeline as the iconic villain Doctor Doom, not Iron Man. While it’s been confirmed that this will not be a Tony Stark variant, a very compelling theory suggests that it could be Doom trying to take over from Iron Man.

Tony Stark’s heroic sacrifice in Avengers: Endgame completed RDJ’s mighty tenure in the MCU. Now, the actor is returning to the franchise to portray one of Marvel’s most infamous villains. As the culmination of the MCU’s Multiverse Saga, 2027’s Avengers: Doomsday concerns alternative timelines and feature characters stepping into unfamiliar roles, making the perfect narrative space to introduce a version of Doctor Doom that has ᴀssumed Tony Stark’s idenтιтy – just as he once did in Marvel Comics.

Doctor Doom Takes Over As Iron Man In Marvel Comics

See Infamous Iron Man

Infamous Iron Man Victor Von Doom cover with half Doom's face and half Iron Man suit

In 2016’s Infamous Iron Man by Brian Michael Bendis and Alex Maleev, Doctor Doom undergoes a radical transformation. Following the events of Civil War II, where Tony Stark is rendered comatose, Victor Von Doom dons the Iron Man armor – not to conquer, but to redeem himself. He attempts to honor Stark’s legacy by becoming a new kind of Iron Man, one guided by logic, intellect, and a desire for redemption rather than ego.

This storyline was one of the most controversial and compelling twists in Marvel Comics at the time. Doom as Iron Man challenged perceptions, explored deep moral questions, and blurred the lines between hero and villain. While this Doom was genuinely trying to be a better man, the world struggled to trust him. Bringing this version of Doctor Doom into the MCU would instantly provide a complex antagonist who’s more than a mere world-conquering tyrant.

Avengers: Doomsday Adapting This Marvel Comic Story In The MCU Would Explain Doctor Doom’s Casting In A New Way

Doctor Doom Could Be Trying To Become Iron Man

The theory that Avengers: Doomsday adapts elements of Infamous Iron Man creates a compelling explanation for why Robert Downey Jr. would return to the MCU not as Tony Stark, but as Doctor Doom. Doom could have ᴀssumed Tony Stark’s appearance, through scientific or magical means, in an attempt to replace Iron Man. This could occur in his original universe or even travel to Earth-616 (the primary MCU universe) to try and fill the void left by Iron Man’s death in Endgame.

This would explain the Russo brothers’ claim that Tony Stark’s death has “repercussions beyond his universe.” In a multiverse where Doom “takes over” after Iron Man’s fall, Stark’s absence becomes a defining moment in Doom’s arc. Perhaps that version of Doom fails, falls into villainy, or crosses into the main MCU timeline seeking to rewrite history. In this light, Doom isn’t just an Iron Man subsтιтute – he’s a distorted echo of what Tony Stark could have become under different circumstances.

Why Tying Iron Man & Doctor Doom’s Stories Together In Avengers: Doomsday Makes Sense

The MCU Needs To Connect The Two To Justify Casting RDJ

Iron Man about to snap his fingers in Avengers Endgame

Connecting Iron Man and Doctor Doom in Avengers: Doomsday is essential. They couldn’t cast RDJ as Doom and not find a way to justify it or connect to Iron Man’s legacy – that would undermine his performance throughout the franchise and his perfect ending in Endgame. Connecting the two would not only honor both characters’ intellectual legacies, but also allow Marvel Studios to explore the same kind of multiversal storytelling seen in Doctor Strange in the Multiverse of Madness.

In that film, audiences saw a world where different characters had filled new roles after their version of Thanos was defeated. That same logic could apply in Doomsday, revealing a universe where Doom took Stark’s place and reshaped the world in his own image. This would also align with Marvel’s ongoing exploration of idenтιтy, legacy, and consequence.

By introducing a Doom who was once a hero – or who believes himself to be one – the MCU can challenge its characters and audience to reconsider what makes someone a villain. It’s not hard to imagine Doctor Doom standing before the Avengers claiming he’s trying to save the multiverse, not destroy it. With Downey Jr.’s gravitas behind the mask, that ambiguity could become one of the most powerful elements in Avengers: Doomsday.