Straight up yandere lmao
"leave me and I kill you"
I get what you're saying, but they're not humans. They're quite the opposite.
so? they're written as pretty mundane even if they're what you would conventionally call monster. The vampire is 100% overpowered by the demon and if we stabilished that he has feelings like any human would, this situation is still a bad one to be in. Like it's not healthy to not be free, I don't care what they are. The author made them ''civilized'' for the most part it just seems out of place to end it in a threat
I don't like at all that he felt the need to threaten his partner so he can never leave him. That's not how a good relationship should go. They should just trust one another and believe they'll be together simply because they want to. None of that ''well you leave me and I crush your soul'' shit