In Chainsaw Man, there's something known as a fiend. Part devil, part human, this is someone who was taken over by a devil to varying points. Some of them are completely devil - such as Power - and some of them still have their human personality left as well.

My character has his human personality but he also has a devil mode that he needs to learn how to control, but makes actions separate from him that he doesn't remember. Unless he learns to work with it, it will always be like this.

Question: I thought of the idea that he could have one entity for his human personality and one entity for his devil form. Would that be allowed?