A newMCUtheory may provide the perfect explanation as to how Robert Downey Jr. can debut as Doctor Doom in Marvel Studios' upcomingAvengers: 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, inAvengers: 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 exactlyhow Robert Downey Jr. can play Doctor Doomafter 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. WhileMarvel 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
A wild new theory shared byReddituser Forever-Royaltyconnects Robert Downey Jr.’s recasting as Doctor Doom to the dramaticevents of 2019’sAvengers: 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 toEndgame. Most notably, theBattle 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 theReddittheory is outlandish and certainly won’t be adapted for theMCU’s upcomingAvengers: DoomsdayandSecret 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 inAvengers: 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 toComicBookthat he had heard"through the grapevine"thatThanos 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’sAvengerscrossover movies.This could play right into the hands of thisReddittheory, as the ending ofAvengers: Endgamecould be twisted, giving Thanos a more pivotal role.
You know, I hear kind of like through the grapevine, that they’re gonna bring [Thanos] back. And there’s theWhat 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.
Josh Brolin reiterated these comments during an October 2024 interview withCollider, which saw him note that he"would do anything that the Russos wanted me to do.“The Russo brothers previously directed Brolin as Thanos inAvengers: Infinity WarandEndgame, and were confirmed to be returning to directDoomsdayandSecret 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 hismore-powerful King Thanos formor 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 ofAvengers: Endgamecould 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 thatChris Evans and Hayley Atwell will also be returning inAvengers: Doomsday, and theories have been rife about who they could play.
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.
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 Americafrom an alternate universe in Marvel Comics.There has also been speculation of an evil Avengers team being included inDoomsday, 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 inAvengers: 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 inAvengers: Doomsdaywould 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 Warsevent in 2015, which will likely form the inspiration for theRusso brothers’Avengers: Secret Warsin 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 Warsstoryline, 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 thatAvengers: Doomsdaycould explore an alternate history that began inAvengers: Endgameis very reminiscent of the animatedWhat 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 toAvengers: Doomsdaydelivering some of the MCU’s darkest moments.
Avengers: Doomsday
Cast
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.
