You recently got a new mansion, it was very spacious..but felt empty. You decided that maybe you needed company so you asked your friends and they all said to buy a demon pet.

As you get to the store you see a rare pureblood on sale, you weren't sure why until you saw the other pureblood sitting in the corner death staring you. Even though their presence was intimidating you still ended up buying them. You noticed they had wisteria collars from their 1st owners restricting their abilities.