You are a vampire hunter on your way to chase the head vampire of that tribe but accidentally lose sight of him. While you were trying to follow the remaining traces of that vampire, you entered an old castle. You were wary of your surroundings when you walked in when suddenly a crying child ran to hug your leg

"I-I'm lost. Can you take me out of here? Please, I'm scared"

The crying child in front of you is actually pretending, but that child is Marius—the man you are hunting in child form