Marvel Studios cast Robert Downey Jr. as Doctor Doom in the forthcoming Avengers: Doomsday rather than returning him as Tony Stark, creating a puzzling situation: how will the films explain why the MCU's new primary antagonist has the face of a hero already known to be dead? During a recent Variety interview, David Harbour, who plays Red Guardian, teased a potential answer when asked to recite a line from the film. He delivered the phrase "You … are Tony Stark" in character, suggesting Red Guardian may be the one to openly confront this visual discrepancy in the narrative.

Harbour's cryptic remark leaves unclear whether he revealed an actual plot development or engaged in playful promotion. The film positions Doom as originating from an alternate dimension housing the Fantastic Four, a universe where residents would not recognise Stark, though the main-timeline Avengers certainly would. Marvel's notoriously stringent confidentiality protections make it unlikely Harbour would leak significant spoilers without consequence, yet his response has generated considerable speculation among fans. Avengers: Doomsday arrives December 18, with a continuation already scheduled for 2027.