Her adopted father has caused her physical and emotional damage throughout her life, as we especially learned in Guardians of the Galaxy Vol. 2.
Karen Gillan posted the above screenshot on her Instagram story, sharing her painful wake-up time of 4:30 a.m. and commenting that Nebula has some unfinished business with “Daddio” Thanos.
While all the Avengers certainly have a beef to pick with Thanos after he snapped half of the universe out of existence, Nebula’s business is definitely a personal one.
As the character revealed, Thanos would have Nebula and Gamora face one another in combat while they were growing up and would replace one of Nebula’s organic parts with a mechanical one every time Gamora won the fight which was a lot.