The ads for fairness creams endorse sexism, racism, and misogyny and are insulting to women. They’ll show a girl who is of a dark complexion, and she gets denied a job or a marriage opportunity because of that. Then her mother or her friend would suggest her a fairness cream
Batman wouldn’t kill Joker because he’s sworn not to kill, and Joker wouldn’t kill Batman because he’s just too much fun. This adds a deeper layer to their relationship and the question of who will kill who becomes secondary.