The most agressive character in AoT is Eren, and he had very affectionate and loving parents, an nice childhood, the bullying he endured was due to his own fiery opposing personality, literally everybody close to him likes him deeply, especially Armin and Mikasa, and the traumas he faces don't really affect his personality until he becomes able to be in the paths where past, present and future happen simultaneously), after that he becomes depressed and his actions are calculated to manipulate. On the other hand, Zeke, who was raised by fanatic parents and grandparents, with no love and affection if not by the former Beast Titan, having had to report his parents to save his own life, then becoming a tool for Marley, forced to kill his own kind, he never became agressive or toxic. Annie had a VERY agressive adoptive father, became a child soldier in a country that hated her existence, and, although she was an assassin, she had morals and never mistreated any of her mates. Levi showed uncountable times that his background never stepped on his morals and values.