Marvel announces what you need to read to understand why Robert Downey Jr. is Doctor Doom

In case you haven’t been near the internet over the last couple of days (which, if so, you are to be admired), Robert Downey Jr. has been confirmed to return to the Marvel Cinematic Universe, much to the excitement of long-time fans of the franchise.

He has, of course, traded out the red and gold of Tony Stark’s armor for the green and titanium of Doctor Doom’s, but the whole enterprise is overshadowed by the fact that roping Downey Jr. back into the fray reads like a slam of the panic button. At the very least, it telegraphs the MCU’s continued intention to lean on fan service with utter impunity.

It is, of course, inappropriate to cast one’s final judgment on a film before it actually comes out, and according to one Deniz Camp of Marvel Comics fame, there could be a bit more nuance to this casting choice than is immediately apparent.

The scribe has taken to X to declare that, if we wish to understand the full scope of Downey Jr.’s casting as Doctor Doom, then it’s imperative that we read the next chapter in Marvel’s ongoing Ultimates series, Ultimates #4.

The series, set to release on Sept. 4 later this year, features an uninhabited Doom mask being inspected by four rats that each seem to possess the powers of one of the members of the Fantastic Four. The Four, of course, will be appearing in Avengers: Doomsday, where Downey Jr. will make his return.

In Ultimates #3, it was revealed that Doctor Doom was playing a key villain role, and seeing as the Ultimates are comprised of modernized versions of the mainstay Avengers (complete with Steve Rogers, Tony Stark, Thor, Hank and Janet Pym, and others), the comic is sure to lay down some key contextual groundwork for Doom’s eventual beef with the Avengers in Doomsday. The fact that the Ultimates were a key inspiration for many of the heroes and storylines of the MCU’s Infinity Saga only backs this up.

One can only hope that the MCU sticks the landing here, but we’ll believe it when we see it, and we’ll all be seeing it when Avengers: Doomsday hits theaters on May 1, 2026.