Marvel Studios knew it had a tall task ahead of the fifth Avengers movie. A superhero movie is only as good as its villain, and the MCU had swung and missed its fair share, including with Kang. The best idea the powers that be could come up with was arguably Marvel's most iconic villain, Doctor Doom, played by none other than Iron Man actor Robert Downey Jr. Doom will terrorize Earth's Mightiest Heroes in Avengers: Doomsday, but he might have some competition.
While promoting his work at New York Comic-Con, John Brolin spoke with ScreenRant about his future as Thanos. The outlet asked specifically about Doomsday, hoping the actor would drop a bombshell that would spark a social media frenzy. Brolin refused to outright confirm anything. However, he didn't shoot down a potential appearance, either, using a word that leaves the door open for another Mad Titan rampage.
"It's kind of like The Goonies, where you go, 'I know you want another one. I want another one, too. But should we do one?' Do you know what I mean? That kind of thing. So, the fact that it's come back around, the fact that it's Joe Russo, the fact that it's one of the most favorite characters I've ever played... Maybe."
This isn't the first time Brolin has given the Russo brothers their flowers. Back in 2025, during an appearance on the Happy Sad Confused podcast, he sang a similar tune.
"If they [the Russos] called me in London right now and said, 'Let's do this,' I'd be like, 'I'll be there tomorrow."
It's unclear whether Brolin received a call between the two events. And he knows better than to spoil something so potentially juicy. But plenty has changed in the MCU that makes another chapter for Thanos feel far more likely.
Thanos' Return to the MCU Seems Like a Foregone Conclusion at This Point
Anyone who frequents Marvel subreddits or fan pages knows they can't scroll long before seeing a panel from Jonathan Hickman's Secret Wars, in which Doctor Doom rips out Thanos' spine. Fans want to see the horrifying image brought to life because it would instantly give Doom credibility and put him in a different league than the Mad Titan.
A brief cameo that ends with Thanos' death might not resonate with Brolin, though, especially since he's already seen his character die twice. Instead, Doomsday could form a partnership that ensures the titular team and their allies have no chance of victory.
Avengers Endgame: Encore revealed that Doom is traveling around the multiverse and collecting powerful individuals. Bruce Banner was his first target, but the Russos have confirmed he won't be his last. A variant of the Mad Titan has the ability to put Doom's team over the top.
Of course, Doom would have to worry about his new ally attempting a coup. But once Doom acquires all the power he's after, he can just rewrite reality and solve his problem with a snap of his fingers. While Thanos wouldn't be happy about being played, he'd have to respect Doom's showmanship.
