Robert Downey Jr. is coming back to the Marvel Cinematic Universe in next year’s Avengers: Doomsday. It’s a big deal because no single actor is as responsible for the success of the MCU as Downey. Had the original Iron Man not been the success it was, we likely wouldn’t be here today, and it’s incredible that the movie worked as well as it did, considering they were basically making it up as they went along.
