needs about 3 activations until its worth the cost, I'd wager thats too much. Suggested buff would be to increase base hp by at least 3.
Things to consider:
The card will rarely return to your deck (unless its useless in the fist place outside catapult and deckout shenanigans against a creatureless deck), especially the first few copies just dont have enough hp. later on the shuffle to deck might be a drawback, as the pull effect never works longer than a turn per activation (thats fair I think).
Voodoo is a lot weaker on lowish hp creatures, as you 'loose' the last instance of dmg.