Not only did he add in the increasingly famous “I love you 3000,” but he also improved a hard-hitting line during an early scene of the film.
Downey improvised the line where Tony Stark calls Steve Rogers a liar, according to co-director Anthony Russo.
Avengers: Endgame was Robert Downey Jr.’s final MCU movie as Iron Man and it sounds like the actor had some free roam to make his own personal touches on the script.