Summary
- Robert Downey Jr.'s return as Doctor Doom avoids a recasting challenge for the MCU.
- The villain's mask ensures anonymity, allowing for strategic reveals.
- The dark future of the Marvel Cinematic Universe is set to be compelling with Downey Jr. taking on the iconic role of Victor von Doom.
Robert Downey Jr.'s new role in the Doomsday cast are confirmed for the team-up film, many are sure to be added who had a significant relationship with Tony Stark. Casting Robert Downey Jr. as the villainous Victor von Doom is a bold choice that will have repercussions on the MCU for years. Featuring Doom as the villain for the next two Avengers films promises to be an exciting replacement for the planned Kang storylines.
The actors have played multiple roles in the MCU that have remained disconnected. This makes the subject of Robert Downey Jr's Doctor Doom all the more interesting, since it's not clear how connected he'll be to Iron Man - though the nature of the character at least means that one of the most challenging components of this recast is easily avoided whatever the case is.

Robert Downey Jr.'s Doctor Doom Casting Explained
Robert Downey Jr. famously played Iron Man in the MCU, so how is he returning as Doctor Doom?
Bringing Robert Downey Jr. Back As Doctor Doom Avoids A Major Recasting Plot Problem
As Doctor Doom, Robert Downey Jr.'s face will likely be obscured during his encounters with the Marvel heroes, due to the villain conventionally wearing a mask that covers his full face in the comics. Beneath the mask, he is often intensely scarred, leading the character to want to conceal his skin. This metal barrier would allow the character's face to be obscured throughout each of his scenes. While audiences will be aware of the face that hides beneath the mask, the Avengers will not.
A number of MCU Doctor Doom theories have surfaced due to the unusual choice of recasting the actor, but whether Doom is a Tony Stark variant or not, it seems the franchise will have to address the fact he looks like Earth-616's Iron Man to some degree. Fortunately for the character’s anonymity, Doom's mask is essentially Victor von Doom's face, and he is thus set to wear this mask throughout much of his film appearances, hiding his connection to Tony Stark and ensuring the franchise can choose when - and if - it addresses the matter.

10 Reasons Robert Downey Jr. Is Perfect For The MCU’s Doctor Doom
Robert Downey Jr. is leaving Iron Man to play the MCU's Doctor Doom, which has led to differing opinions, but the casting works for a few key reasons.
Doctor Doom's Mask Means The MCU Can Choose Its Major Robert Downey Jr. Reveal Moments
Captain Marvel, Spider-Man, and Thor are just a few of the many Avengers likely to return in Doomsday who have a significant link to Tony Stark, and would no doubt feel shocked at seeing the hero's face on a villain's body. However, with a mask being such an integral part of the character's appearance, it is likely that the heroes will not have to face this immediately. Doctor Doom's mask will be able to stay on at all times until reaching points in the story where his reveal would be especially impactful, such as when encountering Peter Parker or Pepper Potts.
Notably, Marvel has followed a frustrating superhero mask trend of constantly needing to show the faces of their performers. As such, only revealing Doctor Doom's face when the time is right would ensure the villain's success in the franchise while also helping address complaints regarding how the MCU has generally handled the topic of masks. While Robert Downey Jr. being a high profile actor means it's likely the MCU will want to prominently show his face, the choice to cast him as Doctor Doom means these moments need to be carefully picked in order to obtain the maximum result.

Doctor Doom: 3 Movies Robert Downey Jr. Could Appear In Before Avengers 5
Robert Downey Jr. is set to play Doctor Doom in the MCU, and there are some movies he could appear in before Avengers: Doomsday.
Robert Downey Jr. has been integral to the Marvel Cinematic Universe from the beginning, and it is exciting to see the actor returning to the fold. Playing an iconic villain like Victor von Doom is a challenging proposition, but the more consideration put into it, the likelier it seems to work. While some may wish for a more traditional iteration of the Doom character, this will surely be impactful for the existing heroes in the MCU. However the franchise chooses to play with his identity in Avengers: Doomsday and beyond, the dark future of the Marvel Universe is incredibly compelling.