If you’re still confused about the whole “Robert Downey Jr. being cast as Doctor Doom” thing, then get in line. Although we don’t exactly know what awaits us in Avengers: Doomsday, here are a few possible explanations (and comic book deep dives) as to why RDJ, of all people, is playing the MCU’s next big bad.

In case you missed it, this year’s San Diego Comic-Con was a bit of a doozy for fans of all things Marvel Entertainment. Studio head Kevin Feige took to Hall H on Saturday night to tease the next wave of MCU content, from Captain America: Brave New World to Thunderbolts to Fantastic Four. 

But perhaps the most head-scratching announcement of all was the confirmation that Robert Downey Jr., who of course played genius-billionaire-playboy-philanthropist Tony Stark, would be returning to the franchise after his “death” in Avengers: Endgame—this time, to play supervillain Victor von Doom, a.k.a. Doctor Doom.

As someone who was in the room when it all went down, the immediate reaction of the crowd when Downey Jr. took off his mask went a little something like “woooouhuhhhhh?” Gauging the temperature of the fanbase has been somewhat of an impossible task (even Gwyneth Paltrow is confused), with one side ecstatic to see the man responsible for “saving” the MCU taking on a new role, and the other side being downright puzzled that of all the popular fancasts for Victor von Doom, the studio landed on Downey.

But regardless of how you feel about his return, it’s going to require a degree of mental gymnastics to explain how Iron Man and Doctor Doom are the same person—well, maybe, that is.

What Is Infamous Iron Man, and why are people convinced it’s the plot of Avengers: Doomsday?

Okay, if you’ve watched all 34 MCU movies (yes, 34) and the accompanying slew of Disney+ TV spinoffs, then you know that all roads lead to the Multiverse. Not only does this give Marvel the perfect excuse to add dozens of “member berries” and fanservice-y moments, but it also gives the MCU power to introduce alternate versions of beloved characters from different timelines, a.k.a. Variants.

We’ve seen this trope play out in Doctor Strange in the Multiverse of Madness, Loki, and most on-the-nose in What If…?, so it wouldn’t be surprising to learn that Doctor Doom might be an (evil) Tony Stark Variant in Doomsday.

And there might just be the perfect comic storyline to back this up. The 2016 Infamous Iron Man comic book run, written by Brian Michael Bendis, follows a version of Doom trying to turn over a new leaf.

To become the best version of himself, Doom drops the whole bad guy act and adopts the mantle of Iron Man, though his longtime foes the Fantastic Four wonder if he’s truly reformed, or if his new identity is part of an elaborate scheme. Oh, and there’s a really cool Doctor Doom/Iron Man hybrid suit.

Promising theory, right? Except there’s one teensey-weensey problem. The Doctor Doom in Infamous Iron Man isn’t Tony Stark. Yes, he might have taken up the Iron Man moniker, but he’s not the man we all know and love from the Infinity Saga.

Because of this, I’m extremely doubtful that Feige and Co. would choose to adapt this comic book run in the next Avengers movie, as Downey Jr.’s casting for this iteration of Doom just … wouldn’t make sense. Is there a way Marvel could explain it? Probably. But if this new and not-so-improved Iron Man isn’t Tony Stark, then surely, why would the MCU recruit the same guy?

Okay, what about Anthony Stark of Earth-11029?

Another theory is that Doomsday will follow Anthony Stark of Earth-11029, as depicted in the 2010 What If? Iron Man: Demon in an Armor #1 comic. In this story, a college-aged Victor von Doom convinces Tony to partake in an experiment that results in their minds being switched, with Doom walking around in Tony’s body and vice versa.

This leads to a big confrontation where Tony eventually one-ups Doom, but it’s too little, too late: Doom has already soured Tony’s reputation and his company, Stark Universal.

Not only would seeing an “evil” Anthony Stark becoming Doctor Doom be ridiculously fun, but it would also make sense for Downey Jr. to play the part. I know what you’re thinking: Didn’t the Russo Bros.

Outright say that Downey Jr. would be taking on the role of Victor von Doom, not Stark? Yes, but technically, he would be Doom in this scenario. There’s certainly some rich comic book lore for Marvel to pull from here, but again, it might not be the direction they decide to go in for Doomsday.

These aren’t even their only options, though Demon in an Armor is the only one where there’s actually a Victor von Doom with Tony Stark’s face.

What if it’s not that deep, really?

Perhaps the least satisfying explanation of all is that Downey Jr.’s iteration of Doom has absolutely zero connective tissue to the Tony Stark of MCU past. While it would be kind of baffling to see Marvel re-introduce the same actor to play a different character within the same franchise, without there even being a reason it’s the same actor, it’s not like this hasn’t happened before.

Although it was the 20th Century Fox universe, Chris Evans, for one, did play Johnny Storm in the Fantastic Four movies long before he picked up the shield for Captain America.

After all, this is the Multiverse Saga, so maybe we’ll just have to sit back, relax, and put our trust in Kevin Feige and the Russos. Doom’s not exactly known for showing his face, so maybe it doesn’t even matter that the man playing him looks exactly like the MCU’s Tony Stark, and all the varied Iron Man x Doom source material provides plenty of material to draw on, since the MCU is going to make changes to anything it adapts.

Plus, we all know Robert Downey Jr. is an extremely capable actor, so dare I say it might be … fun? to see him wearing a different hat in the MCU—this time, as one of Marvel’s most formidable comic book villains. Either way, here’s hoping we get a more concrete answer soon.