Kevin Feige has confirmed that Doctor Doom is not a variant of Tony Stark in Avengers: Doomsday.
When speaking with Empire Magazine, Marvel Studios boss Kevin Feige debunked the popular fan theory that Doctor Doom and Tony Stark have a shared connection in the multiverse. Fans have speculated that Doom is a “variant” of Stark, since Robert Downey Jr. plays both characters. Variants are other versions of a character across the multiverse. We’ve seen this with the three Spider-Men, Wolverine, and Loki, so naturally, some fans thought this may all be an elaborate way to explain how Robert Downey Jr. is also playing Doom… turns out, it’s not.
“Is Steve Rogers a Johnny Storm variant?” asked Feige. “People wondered, ‘Is Doom just a variant of another character? Is this just a shortcut to bringing back another character?’ The answer is no. He’s Victor Von Doom.”
Avengers: Doomsday Trailer: First Look at Doctor Doom
As for what Doom’s whole deal is, the creative team behind the film teased what kind of energy he brings and why he is the way he is. The Russo Brothers, who are directing the film,
