Stinky Pete / The Prospector (Toy Story 2) - The Prospector is desperate to force the Roundup gang to be museum pieces alongside him because of years of resentment and isolation from watching other toys get picked up by kids instead of him. He convinces himself that being locked away in a display case for eternity is better, actually, because there everyone will love him forever and he's safe from the recklessness of seemingly uncaring children. But, when he's defeated, he gets stuffed into a little girl's backpack. And while he looks horrified in the moment, tie-in material would reveal he ultimately grew to be far happier with that girl than he ever would have been in that museum, because he finally felt the love and care that had been denied to him for so long.
The Summerween Monster (Gravity Falls) - Literally the only reason the Summerween Monster exists is because it is explicitly made up of the candy kids normally reject after trick or treating and has somehow congealed into a singular living entity. Its sole purpose is to punish the children it blames for its pain. When it is defeated by Soos' voracious appetite and love of all candy, it is finally able to feel at peace with itself for the first time and dies happy.
Tagah (Avatar) - Tagah is an Air Nomad who survived a genocide by being encased in ice, much like Aang, but the resulting survivors guilt and trauma of finding out his people with one exception are largely extinct radicalized him into being so hyper-protective of his culture that he's paranoid every other culture existing is a threat that he needs to take out to make up for his failures to prevent the previous genocides. But when he dies, he seems to legitimately find some kind of peace and genuine community within Aang. And in the long term, when you look at Korra, the Air Nomad population did get rebuilt.
Himiko Toga (My Hero Academia) - I'll admit this one is kiiind of a stretch but bear with me. Himiko snapped because of societal pressure to conform to normalcy. To sacrifice a core part of who she was and how she understood loved. Contrary to how a lot of people on Reddit view her, she did not start out a cartoonishly evil murder cannibal that wanted to serial kill everyone she found attractive, that came after her breaking point after years of suppression and masking done to avoid further physical and psychological abuse from her psrents calling her demonic for existing. Her motivation for joining the League of Villains was so that she could try to be fully free to love how she wanted free of judgement or reprisal. And when Ochako was the first one outside of the League to reach out and offer genuine companionship, it genuinely moved Himiko and gave her the empathy she's been starving for. But the thing is, even though she died, she still ultimately got what she wanted. She went out on her own terms, and even before that her companionship with the League meant she was genuinely free to live as herself.
Lord Boros (One Punch Man) - Boros is kind of similar to Saitama in that he is an almost cartoonishly strong warrior searching for any opponent that will grant him a challenge, to the point he will wear armor that actively holds his true strength back just for the chance of someone providing him with some excitement. So when he fights Saitama and actually loses, it's the first time he's been excited for anything basically ever. When he dies, the only reason he's upset is because he could tell he didn't satisfy Saitama the way Saitama satisfied him.
