Ever since the announcement of Robert Downey Jr becoming Doctor Doom, the question has been what version of Doom RDJ will be portraying in the MCU. The fact that RDJ also played Iron Man, and that Tony Starks face is iconic and recognizable in the main MCU universe, it stands to reason that the Doom he is portraying helms from a different universe. While there are an infinite number of possibilities for how Doom enters the MCU, one possibility from more recent Avengers comics may be the introduction of Doom Supreme.