Vadriel
Bite my shiny metal ass!
Quite possibly the most straight-up broken card I've ever seen...can turn any army into a brutal force of destruction...if my Slivers didn't already have half of this stuff, I'd totally run one. Now swarm decks can be even more deadly, as any one of the little buggers can be a badass.
I don't personally know the restrictions on this card, but I'd assume there has to be some form of it, because I can't imagine a deck where this card wouldn't come in handy.