Right now, we have expel and summon (there's the house guest, but that's not actually a spell), but how about a third type which allows you to polymorph into that creature for a few rounds (moon, 0 pips like any other polymorph spell)? During that time, you would get its deck, masteries, and stats, along with any resistances and boosts that it may have, but no cheats of course.
