Possession

Possession is the co-inhabitance of a body by both a magic-user (commonly a fey) and the original owner of the body.

Process
In order to possess a body, the magic-user must first establish an initial sympathy with it. From this, the magic-user creates a mimicry between the brains of the body and of the magic-user, thereby generating a similarity sympathy that can be used to sustain the possession near-indefinitely.

Fey possession
Fey possession, or the possession of a body by a fey, is the most common type of possession.

Grimalkinism
Grimalkinism is the most common type of possession, where the fey inhabits the body of an animal. This animal is often of a species that is relatively intelligent, such as ravens, or of a pack species. The main benefit to this type of possession, over possession of a hominid, is that the fey's will and intelligence generally overpower that of the animal's. An animal inhabited by a fey is known as a grimalkin.

Many grimalkins enter into a mutually beneficial relationship with a hominid, where the grimalkin acts as a mentor or servant to the hominid, and the hominid takes care of the grimalkin's need for shelter and sustenance. Such a grimalkin is known as a familiar.