Marvel fans share worrying concern over Robert Downey Jr returning to MCU as Doctor Doom

Robert Downey Jr just pulled a Jordan Belfort 'I'm not f**king leaving' special after announcing his shock return to the MCU.

The Oscar-winning actor, 59, pretty much revived his career after making his MCU debut in 2008's Iron Man, before going on to appear in ten more films throughout the franchise.

Robert Downey Jr played Iron Man for 11 years. (Disney)

Despite Tony Stark's death in Avengers: Endgame, Downey Jr announced his return in dramatic fashion.

Reminiscent of the way he was revealed as Iron Man in the first movie, the actor took off his Dr Doom mask on stage to huge applause at San Diego Comic-Con on Saturday (27 July).

Watch below:

He told a room of excited fans: "New mask, same task. What'd I tell you, I like playing complicated characters."

Joe and Anthony Russo said they will direct Downey Jr's next appearance as Doctor Doom in the next two Avengers movies - Avengers: Doomsday and Avengers: Secret Wars.

“When we directed Avengers: Endgame, Joe and I truly believed that it was the end of the road for us in the Marvel Cinematic Universe,” Anthony Russo told the Comic-Con crowd.

“In the time since, through a very special story, Joe and I have come to potentially see a road forward with you.”

The actor unleashed his inner Jordan Belfort. (Matt Winkelmeyer/Getty Images)

Meanwhile, some fans are worried at how the Oppenheimer actor is going to shake off Tony Stark in his new role.

Having played the Iron Man character for 11 years, people might find it hard seeing him as the Dr Doom supervillain.

Taking to X, one fan wrote: "Marvel actually dug a deeper hole for themselves by bring RDJ back.

"Yes he will save their dying franchise but it will be an even harder job to take that Iron Man image off people's mind.

Another added: "It will be the end of Marvel if they mess up the next two Avengers movies."

"Am I the only one that’s more worried than excited???

He's back. (Jesse Grant/Getty Images for Disney)

"Love RDJ but like how tf are they going to make this work when we all just cried about Iron Man’s death a few years ago.

"Like they literally just referenced Tony in Deadpool and Wolverine LMAO."

While a third penned: "I have a hard time seeing RDJ as Doom, it'll be too weird imo..."

However, many fans were buzzing with the news, as one tweeted: "I FW THIS SO MUCH WHAT A WAY TO BRING HIM BACK."

While a second hoped: "WAIT WHAT!!! HOPING THIS IS A STARK VARIANT WHO TURNED INTO DOOM."

Avengers: Doomsday will premiere in May 2026 with Avengers: Secret Wars following in May 2027.