Robert Downey Jr"s Doctor Doom Was Created By Thanos According To Avengers: Endgame MCU Theory
A new MCU theory may provide the perfect explanation as to how Robert Downey Jr. can debut as Doctor Doom in Marvel Studios" upcoming Avengers: Doomsday. Following a five-year hiatus from the MCU, in which he previously portrayed Tony Stark"s Iron Man, Academy Award-winner Robert Downey Jr. was confirmed to be coming back, but not as Iron Man. Robert Downey Jr. will debut as Victor Von Doom, a.k.a. Doctor Doom, in Avengers: Doomsday, replacing Thanos and Kang the Conqueror as the MCU"s new primary antagonist, but this casting has caused some confusion.
Since he was confirmed to be returning to the MCU, theories have been rife regarding exactly how Robert Downey Jr. can play Doctor Doom after spending over a decade as Iron Man. Doctor Doom is arguably Marvel Comics" most iconic supervillain, so it makes sense that Marvel Studios would want a recognizable and beloved actor in the role, but Downey Jr. already had his time in the MCU. While Marvel Studios is yet to explain Downey Jr."s recasting, a new MCU theory may have already found the perfect answer to this huge development.
RDJ’s Doctor Doom Comes From Thanos’ New Universe: MCU Theory Explained Thanos Almost Created A New Reality In Avengers: Endgame Close A wild new theory shared by Reddit user Forever-Royalty connects Robert Downey Jr."s recasting as Doctor Doom to the dramatic events of 2019"s Avengers: Endgame. The Phase 3 crossover movie kicked off many storylines that got developed further in the Multiverse Saga, so it makes sense that Marvel Studios could also connect Doctor Doom to Endgame. Most notably, the Battle of Earth almost ended with a younger Thanos snapping his fingers and restarting the universe. In one reality of the multiverse, he must have completed this mission.
Most of the Reddit theory is outlandish and certainly won"t be adapted for the MCU"s upcoming Avengers: Doomsday and Secret Wars. However, the theory posits that the new universe created by Thanos in one reality of the MCU"s multiverse could be home to variations of the MCU"s own heroes, which could clearly explain how Robert Downey Jr. can return while portraying an entirely new character. This could show audiences what might have been had Tony Stark not stolen the Infinity Stones and snapped his own fingers in Avengers: Endgame, paving the way for an even more powerful villain.
MCU Theory Perfectly Explains Thanos’ Teased Return Josh Brolin Has Teased Thanos' Return To The MCU![]()
Back in February 2024, Josh Brolin, who played the Mad Titan, Thanos, in several MCU movies, revealed to ComicBook that he had heard "through the grapevine" that Thanos could be returning to the MCU. His comments suggested that there were already firm plans for Thanos to come back, and the most obvious place for this to take place would be in Phase 6"s Avengers crossover movies. This could play right into the hands of this Reddit theory, as the ending of Avengers: Endgame could be twisted, giving Thanos a more pivotal role.
[indent] You know, I hear kind of like through the grapevine, that they"re gonna bring [Thanos] back. And there"s the What If...? series and that"s a different kind of Thanos and all that. But I don"t know in the Marvel world whether they"re going to bring him back, but I didn"t know that he was the most killed-off Marvel villain... You learn something new every day.
[/indent]Josh Brolin reiterated these comments during an October 2024 interview with Collider, which saw him note that he "would do anything that the Russos wanted me to do." The Russo brothers previously directed Brolin as Thanos in Avengers: Infinity War and Endgame, and were confirmed to be returning to direct Doomsday and Secret Wars. There"s nothing to stop them bringing Thanos back with them. This all means it may not be too long before the Mad Titan is back in the MCU, perhaps in his more-powerful King Thanos form or as another variant.
Thanos Theory Opens The Door For More Twisted MCU Characters Robert Downey Jr. Isn't The Only Returning MCU Veteran![]()
The idea that the new universe Thanos could have created at the end of Avengers: Endgame could contain twisted, perhaps villainous versions of some of the MCU"s most iconic superheroes is a very interesting avenue to be explored. Since Robert Downey Jr. is coming back to the MCU to play a villain, Doctor Doom, other MCU veterans could follow suit. This idea has perhaps been supported by the recent news that Chris Evans and Hayley Atwell will also be returning in Avengers: Doomsday, and theories have been rife about who they could play.
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Related 10 MCU Actors We Desperately Want To Return In Phase 6 After Robert Downey Jr & Chris Evans’ Avengers: Doomsday Castings Robert Downey Jr. and Chris Evans have been confirmed to be returning to Marvel in Avengers: Doomsday, and many more MCU veterans could join them.
Posts Steve Rogers and Peggy Carter would, of course, be the most obvious choices. However, Chris Evans has been theorized to be debuting as the evil, HYDRA-indoctrinated version of Captain America from an alternate universe in Marvel Comics. There has also been speculation of an evil Avengers team being included in Doomsday, which could easily have formed in this new Thanos-ruled reality. This could create some fun opportunities for some MCU veterans, who could discover darker sides to their classic MCU characters in Avengers: Doomsday.
Doctor Doom & Thanos’ Connection Could Be Important In Avengers 5 & 6 Doctor Doom & Thanos' Secret Wars Moment Could Be Adapted For The MCU![]()
Having Robert Downey Jr."s Doctor Doom helm from a reality created and ruled over by Thanos in Avengers: Doomsday would be a fantastic way to adapt their tumultuous Marvel Comics relationship. Thanos and Doctor Doom have never seen eye-to-eye, and this was perhaps never more evident than during Marvel Comics" Secret Wars event in 2015, which will likely form the inspiration for the Russo brothers" Avengers: Secret Wars in 2027. One moment in this story saw Doctor Doom remove Thanos" skeleton from his body, which would be incredible to see in live-action.
After incursions destroyed the multiverse in Marvel Comics" Secret Wars storyline, Doctor Doom absorbed power from the otherworldly Beyonders and built Battleworld from fragmented realities. He set himself up as God Emperor Doom, ruling over a Kingdom of variants who had no memory of their past, until Earth-616"s Mister Fantastic returned to bring his empire down.
If this scene is adapted into the live-action MCU, this act could possibly be fueled by years of anger and resentment towards Thanos, as Doctor Doom may have been suffering under the Mad Titan"s rule for his entire life. The idea that Avengers: Doomsday could explore an alternate history that began in Avengers: Endgame is very reminiscent of the animated What If...? series, which has been speculated to be moving into live-action following its conclusion with season 3. This theory perfectly explains Downey Jr."s Doctor Doom, and could lead to Avengers: Doomsday delivering some of the MCU"s darkest moments.
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Avengers: Doomsday Superhero 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 5 will also mark the beginning of phase 6 of the MCU.
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Since he was confirmed to be returning to the MCU, theories have been rife regarding exactly how Robert Downey Jr. can play Doctor Doom after spending over a decade as Iron Man. Doctor Doom is arguably Marvel Comics" most iconic supervillain, so it makes sense that Marvel Studios would want a recognizable and beloved actor in the role, but Downey Jr. already had his time in the MCU. While Marvel Studios is yet to explain Downey Jr."s recasting, a new MCU theory may have already found the perfect answer to this huge development.
RDJ’s Doctor Doom Comes From Thanos’ New Universe: MCU Theory Explained Thanos Almost Created A New Reality In Avengers: Endgame Close A wild new theory shared by Reddit user Forever-Royalty connects Robert Downey Jr."s recasting as Doctor Doom to the dramatic events of 2019"s Avengers: Endgame. The Phase 3 crossover movie kicked off many storylines that got developed further in the Multiverse Saga, so it makes sense that Marvel Studios could also connect Doctor Doom to Endgame. Most notably, the Battle of Earth almost ended with a younger Thanos snapping his fingers and restarting the universe. In one reality of the multiverse, he must have completed this mission.
Most of the Reddit theory is outlandish and certainly won"t be adapted for the MCU"s upcoming Avengers: Doomsday and Secret Wars. However, the theory posits that the new universe created by Thanos in one reality of the MCU"s multiverse could be home to variations of the MCU"s own heroes, which could clearly explain how Robert Downey Jr. can return while portraying an entirely new character. This could show audiences what might have been had Tony Stark not stolen the Infinity Stones and snapped his own fingers in Avengers: Endgame, paving the way for an even more powerful villain.
MCU Theory Perfectly Explains Thanos’ Teased Return Josh Brolin Has Teased Thanos' Return To The MCU
Back in February 2024, Josh Brolin, who played the Mad Titan, Thanos, in several MCU movies, revealed to ComicBook that he had heard "through the grapevine" that Thanos could be returning to the MCU. His comments suggested that there were already firm plans for Thanos to come back, and the most obvious place for this to take place would be in Phase 6"s Avengers crossover movies. This could play right into the hands of this Reddit theory, as the ending of Avengers: Endgame could be twisted, giving Thanos a more pivotal role.[indent] You know, I hear kind of like through the grapevine, that they"re gonna bring [Thanos] back. And there"s the What If...? series and that"s a different kind of Thanos and all that. But I don"t know in the Marvel world whether they"re going to bring him back, but I didn"t know that he was the most killed-off Marvel villain... You learn something new every day.
[/indent]Josh Brolin reiterated these comments during an October 2024 interview with Collider, which saw him note that he "would do anything that the Russos wanted me to do." The Russo brothers previously directed Brolin as Thanos in Avengers: Infinity War and Endgame, and were confirmed to be returning to direct Doomsday and Secret Wars. There"s nothing to stop them bringing Thanos back with them. This all means it may not be too long before the Mad Titan is back in the MCU, perhaps in his more-powerful King Thanos form or as another variant.
Thanos Theory Opens The Door For More Twisted MCU Characters Robert Downey Jr. Isn't The Only Returning MCU Veteran
The idea that the new universe Thanos could have created at the end of Avengers: Endgame could contain twisted, perhaps villainous versions of some of the MCU"s most iconic superheroes is a very interesting avenue to be explored. Since Robert Downey Jr. is coming back to the MCU to play a villain, Doctor Doom, other MCU veterans could follow suit. This idea has perhaps been supported by the recent news that Chris Evans and Hayley Atwell will also be returning in Avengers: Doomsday, and theories have been rife about who they could play.
Related 10 MCU Actors We Desperately Want To Return In Phase 6 After Robert Downey Jr & Chris Evans’ Avengers: Doomsday Castings Robert Downey Jr. and Chris Evans have been confirmed to be returning to Marvel in Avengers: Doomsday, and many more MCU veterans could join them.Posts Steve Rogers and Peggy Carter would, of course, be the most obvious choices. However, Chris Evans has been theorized to be debuting as the evil, HYDRA-indoctrinated version of Captain America from an alternate universe in Marvel Comics. There has also been speculation of an evil Avengers team being included in Doomsday, which could easily have formed in this new Thanos-ruled reality. This could create some fun opportunities for some MCU veterans, who could discover darker sides to their classic MCU characters in Avengers: Doomsday.
Doctor Doom & Thanos’ Connection Could Be Important In Avengers 5 & 6 Doctor Doom & Thanos' Secret Wars Moment Could Be Adapted For The MCU
Having Robert Downey Jr."s Doctor Doom helm from a reality created and ruled over by Thanos in Avengers: Doomsday would be a fantastic way to adapt their tumultuous Marvel Comics relationship. Thanos and Doctor Doom have never seen eye-to-eye, and this was perhaps never more evident than during Marvel Comics" Secret Wars event in 2015, which will likely form the inspiration for the Russo brothers" Avengers: Secret Wars in 2027. One moment in this story saw Doctor Doom remove Thanos" skeleton from his body, which would be incredible to see in live-action.After incursions destroyed the multiverse in Marvel Comics" Secret Wars storyline, Doctor Doom absorbed power from the otherworldly Beyonders and built Battleworld from fragmented realities. He set himself up as God Emperor Doom, ruling over a Kingdom of variants who had no memory of their past, until Earth-616"s Mister Fantastic returned to bring his empire down.
If this scene is adapted into the live-action MCU, this act could possibly be fueled by years of anger and resentment towards Thanos, as Doctor Doom may have been suffering under the Mad Titan"s rule for his entire life. The idea that Avengers: Doomsday could explore an alternate history that began in Avengers: Endgame is very reminiscent of the animated What If...? series, which has been speculated to be moving into live-action following its conclusion with season 3. This theory perfectly explains Downey Jr."s Doctor Doom, and could lead to Avengers: Doomsday delivering some of the MCU"s darkest moments.
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Avengers: Doomsday Superhero 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 5 will also mark the beginning of phase 6 of the MCU.
Release Date May 1, 2026 Upcoming MCU Movies
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Captain America: Brave New World
Release Date February 14, 2025
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Thunderbolts*
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The Fantastic Four: First Steps
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Avengers: Doomsday (2026)
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