Love the flavor of the classes, items, and special abilities, and the strange interactions with spirits. It's a little unclear to me whether the spirits are necessarily always on your side when summoned; if I were to run it, I might say that you can summon an uncontrolled spirit as an action, and bind it in a separate action, just to keep things scary, but I'm guessing that may just be me being mean, given that it already costs you HP to summon them. :)