It's based on a boy who was born by a werewolf in the days that wolves were regarded as agents of hell due to how they would assassinate people during full moon.There was a group of supernatural beings who were referred to as the shepherds because they would protect the humans from the werewolves, so when the baby was born a group of shepherds were sent to assassinate the werewolves but in the process of liquidating,one of the shepherds sympathesises with the baby boy and he decides to take it and make it one of the shepherds,but by doing this he endangers every creature.