Very decent for extended matches in Arena where the game usually goes into topdeck wars, but the nice part about it is that it adds another dimension to things. Not sold on it being a staple in many decks in constructed, but with 130 cards in the Expansion, it is hard to predict.
It would be some potential if it had a type, like Beast or something, and better body. Ultimately it is worse Nefarian, which sees some play due to being a dragon. A huge dragon. But this card has none of those things. It's underpowered stat wise and doesn't belong to any synergy.
I can see this being awesome. I really like Nefarion, and this guy can get more value from a thing you are already using. It can't be worse than getting a spare part, and value is value. This will end up with the same QQ threads as Thoughtsteal or anything else that can win you the game or lose you the game.