After consulting inner demons, and being kept up all night by doing so, I have run three basic diagnosis, one Virmir has a very odd flea that is making it hard for him to think strait, two my diagnosis from last night was right and he has a Zoonotic Infection, three which is most likely your response "Magic" which is a heap of nonsense in the eyes of a doctor unless your ideal cure is snake oil and pine leaves. To continue any of these theories I need to know symptoms of the infection or flea bite. I would also like to point out how basic of a plot this is for a story, But then again these are not really my thoughts going on in my head, are they? and they hate being woken up, and I hate being up. I would also like to point out that this infection would also do the same thing as possession, which mean Virmir would at least remain actively conscious of what he is doing.