I forget whether this is a manga or a manhua, this is about a witch who moves bodies in a boy. The world plot is a modern world where there are many monsters and people work by hunting down these monsters and then selling their body parts. The MC has a memory about magic. He became overpowered and clever in magic formations. In his home he made an energy gathering formation to train himself. He tried to look for races other than humans in the world. I really forgot the title. Help me! Thank you!