Robert Downey Jr. has fully immersed himself in the preparation for his new villain role in the next Avengers movie.

The Oscar-winning actor shocked fans last year when he announced he was returning to the Marvel Cinematic Universe (MCU) to play the Fantastic Four villain Victor Von Doom/Doctor Doom in 2026’s Avengers: Doomsday.

Directors Joe and Anthony Russo revealed in a recent interview with Entertainment Tonight that Downey Jr. was in the middle of writing a backstory for the character to prepare for the upcoming shoot.

“It’s a very intense process developing the character. He’s so immersed in it. He is so dialled in,” Joe said. “(Downey’s) writing backstory, costume ideas… I think he just loves really rich, three-dimensional characters and I think he sees a real opportunity here with that character.”

The Russo brothers previously directed Avengers: Infinity War and Avengers: Endgame, in which Downey Jr.’s original MCU character Tony Stark/Iron Man was killed off. They will reunite with the Oppenheimer star on the set of Doomsday, which will begin filming in London this summer.

In a separate interview with Collider, the directing duo explained that they’ve worked very hard to maintain secrecy and ensure paparazzi can’t take pictures of the sets and characters during filming.

“We’re pretty good about shutting that down,” Joe stated. “We don’t want people getting photographs, so we are being pretty stringent.”

While most of the filming will be done in soundstages, the directors have picked outdoor locations that will “hopefully be effective with that”.

The Russos are currently promoting their new movie, The Electric State, which will premiere on Netflix on 14 March.

Avengers: Doomsday will be released in May 2026, followed by Avengers: Secret Wars the following year.

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