10 Worst Things The Joker Has Ever Done To Harley Quinn
1. He Seduced Her
Whilst the Joker may be insane, he isn't stupid. The Harlequin of Hate has a deviously sharp mind and an expert understanding of psychology. Thanks to that, he was able to manipulate Harley into falling in love with him.
Harleen Quinzel was a young and promising psychiatrist at Arkham Asylum who took a special interest in the Joker. While trying to cure him though, the Joker flipped things around and began preying on her own weaknesses.
He spun her a completely made up backstory including classic psychological triggers like an abusive father to lure Quinzel into thinking she could fix him. Then he played on her insecurities of her lonely and dull life to seduce her as a man "who can make you laugh again".
From there, he used her to escape the asylum multiple times before eventually convincing her to join him as his sidekick.
It was a move that destined Harley Quinn to a lifetime of pain and abuse and demonstrated that the Joker doesn't care about her beyond making her the punchline to a joke; by driving the person supposed to help him insane, he proved his key belief that chaos will always triumph over order.