.Wonder is actually taking the Russo Bros. back to instruct the upcoming pair of Avengers movies The VergeRobert Downey Jr. Sets Marvel Return as Winner von Ruin in 'Avengers: End Ofthe World' VarietyRobert Downey Jr. To Officially Return To The MCU As Doctor Ruin Forbes' Avengers' superstar Robert Downey Jr. comes back to Wonder-- however as Medical Professional Doom U.S.A. TODAYMCU's Doctor Ruin Appointed finally for Avengers: End ofthe world, and It's Robert Downey Jr. |SDCC 2024 IGN.