Robert Downey Jr returning to the Marvel Cinematic Universe as Doctor Doom makes the concept of the franchise bringing Tony Stark back as an AI like they did in the comics all the more interesting. With Iron Man being the hero who brought the MCU timeline to life - and the hero who bravely sacrificed himself to save half of all life in the universe in Avengers: Endgame - it's understandable that his story is rightly considered one of the franchise's biggest. Interestingly, upcoming MCU releases look as though they might also add new chapters to Iron Man's story.