After Fein's transformation into a demon, he and Sofia decided to investigate a series of strange disappearances in the nearby town. They found that the disappearances were linked to a group of powerful mages which were actually people that made a contract with demons. The only way for humans to wield magic lower is to sell their soul to the demon and enter a contract. At that time, demons can feedback their magical energy to humans. It's like they are letting the humans borrow their magical power. The group of mages were using dark magic to capture innocent people and drain their life force for their own purposes.
Fein and Sofia arrived at the town, where the strange disappearances were taking place. As they walked through the town, Fein's keen eyes surveyed the surroundings, looking for any clues that might lead them to the perpetrators.