A man named Hector goes to the castle to get revenge on a man named Isaac, who was responsible for the death of Hector's love Rosario. Hector has the ability called Devil Forging, which he can use various materials and combine them to make a strong weapon for himself to fight against. Hector is aided by the Innocent Devils (AKA IDs), who are monsters that follows Hector and helps him get through tough situations. Hector will also encounter various people for the mystery about the Curse of Darkness. Will Hector be able to find and defeat Isaac and end the Curse of Darkness?