He would be a fae, more specifically, a forest imp. Not quite so dark as Phrenesis, but being a physical creature perhaps Phrenesis could even possess him for short amounts of time (anything to amuse my character). Also, Phrenesis seems to have a personal vendetta against Ada, whereas my character would have no such motivation. He would also be very crafty and clever, perhaps he could aid Phrenesis in trying to take down Ada, or even acquire new bodies for him (one of his mischiefs is getting travelers lost in the forest) to possess. 

That is, if Lord Pie likes the idea.