"Why couldn't you have been better with me?"
For when a character gets a redemption arc, but only after causing permanent damage to a character that breaks away from them before they redeem.
Donna (The Good Place) after a lot of heaven and hell shenanigans, Eleanor finds out her neglectful mom faked her death and goes to meet her, fully planning revenge on her mom for years of neglect. She finds that Donna now has a new daughter that she treats much better. Eleanor tries to prove that she's still just as bad, but fails.
Alan (Animator Vs Animation) In a prequel, we get to see what Alan did before the series started, that being torturing a stick figure he named "victim" over and over again. Victim eventually escapes but lives with eternal PTSD along with vengeance for Alan. Meanwhile, Alan moves on and grows as a person, eventually having a good relationship with the main cast of stickmen that he treats well.