(Okiiiiiiiii-numero uno and yes I KNOW you don't like vampires but this one's so good and I can make plottttttttttttttttttttttttttttt-)
Vampire Prince
Person A is a vampire Prince. They rule the kingdom and sit on the throne, but it's all with reluctance. Every year a sacrifice is brought from a nearby village for The Vampire Royalty. They kidnap Person B and take them to the castle