Priests don't really have a particularly crazy way to put, specifically, big minions in their hand, from outside of their deck that I know of(Other than some work with the new Spirit, but those will cost 1 mana anyway, so that's not really too beneficial). They do have ways to steal their opponent's deck, which CAN give you big minions you'll want to play, but will it? not always.
Hopefully this means priest will get ways to support this card, it seems pretty fun regardless, almost like a slightly slower Boomship.
Hmmm, I set this as very good. I know that somehow, someone will find a way to make this card OP, mana cheating always leads to crazy plays, and if this can be played on curve and somehow bring 2 or 3 minions with it, that is a good swing.