One MCU theory could explain why Robert Downey Jr. is back to play Doctor Doom: Tony Stark was actually a Doom variant.

The Collector will also reappear in “Guardians of the Galaxy,” thus pushing the Infinity War storyline forward. This after-credit scene sets up “Avengers ... Loki's scepter. Tony Stark ...

Instead, it focuses on the opening act of the film, setting up where and what our heroes have been doing since the devastating events of Avengers: Infinity War. Tony Stark and Nebula seemingly ...