This seems quite interesting.

I do have a few questions. In your setting, what is the nature of these supernatural beings? Are they scientifically explainable phenomena, or are they completely mystical in nature? Are they only "ghosts" or are can they take the shapes of supernatural beings of folklore (fairies, youkai, etc)? Do they manifest on their own, or are they shaped by human belief?

The last question is particularly important to the character concept I have in mind. A self-described con man that specializes in "impostors," and can deceive creatures into defeating themselves.