Looks like a great idea.
My recommended change, other than those already mentioned (Ice bolt & Nightmare):
Change the acceleration for a Gravity Pull. If combined with BB, it can grant you that one extra turn you might need for survival, or can be used as very effective CC. As you said, there's no real target for it in the deck, so having it does no good. There are no valid targets for rage potion either (except the Angel), so you may want to change that as well. Or give it targets. As it is, it will almost always be used as CC (exception being a lucky nymph or mutation).
From Death, if you have no better idea, Skull Shield may be great to have. Another card that introduces players to RNG hax or failure. Or a random Boneyard as synergy for Fallen Elf.. Nevertheless, Flesh Spider is great for Adrenaline.
