Robert Downey Jr. also known as Iron Man in the Marvel Universe, he plays a very important role in Avengers: Infinity War and Avengers: Infinity War, he also has his movies based around him. Such as Iron Man, Iron Man 2 and many others.
SPOILERS AHEAD!!!
Robert Downey Jr. or Tony Stark no longer wanted to act in movies, because he is simply too old for that much action, so he asked Marvel for them to add a way of him not being in the MCU, so at the end of Endgame he is killed by the Infinity Gauntlet Snap.
Coroana! ;|
