CASPER

Over the course of the game, Casper evolves from a cold enforcer who comes for your soul to a tender lover willing to do anything. He's caring: he might bring flowers simply because the protagonist mentions they've never been given, or come to nurse someone sick, ruining the kitchen in the process, but genuinely trying. He's jealous, but he also learns to accept the protagonist's pet as part of the family.
In the game's best endings, Casper finally drops the mask. He admits that the protagonist has melted his heart, which he thought was forever frozen. For the sake of his beloved, he is ready to defy the system itself, hide him, escape, or even lose his immortality to become a mere mortal and open a flower shop with him.
So, Casper isn't just another "bad guy with a good heart." He's a profound character whose tragedy lies in the fact that his job is to take lives, and his salvation lies in his ability to appreciate them. He's a Reaper who forgot what it means to live, and through love, he rediscovers it, risking his immortality. His story is a tale of how even in the most strict and heartless system, the seeds of true emotion can sprout, changing everything.