I'm thinking of makin him Pula's (nearly) mindless servant. He basically just grunts and cleans around the mansion. Pula has to hunt for both of them, but being a vegan in his past life makes it difficult for him to feed on humans so he eats animal blood.
Backstory: He was in an accident that left him in a coma. His family begged a vampire to save him, but when they did he stayed in this zombie-like state. His family soon abandoned him and Pula found him wandering and starved. #Abenjamin