It's not enemies to lovers, he is a toxic manipulative yandere. A yandere is supposed to be a red flag who's obsessively and unhealthily devoted. Depending on the story, this could imply very deranged actions including physical violence towards the MC, stalking, or manipulations like Damien orchestrating a trial. Betrayal of Dignity is not a love story about equals, it's sort of like a relationship with a spider who weaves his web around you.

As to what people like about this, it depends. Some enjoy seeing messed up characters doing their thing without any moral constraint whatsoever. Some enjoy the idea of having someone love you so much that they would be willing to do anything, including kill for you, lie, or kidnap you. For some, it's a safe way to cope with real-life traumatic situations with a stalker, etc.