William and his friends go to an abandoned asylum to investigate hauntings, but things go south when they are attacked by demonic monsters. William then gets supernatural abilities to fight against the monsters. He then is challenged by a stronger demonic monster. William is no match against the monster. William was saved in time by another person named Yazen. After the battle, Yazen then takes William to the campus called the Fiend Hunters Association. William then trains to become a hunter, and to become stronger to protect humans from the fiends.