I'm a bit worried about this + fractal. You could fractal a BLight or some other 0-cost creature, sacrifice them all to get a full hand of cards, get skeletons from graveyards, play all your cards, sacrifice your skeletons, get another full hand...
You see where I'm going with this, right? Fractal BLight's already somewhat possible with death, so it's not like the concept's unfeasible, either. You could use a soul catcher or something to get the quanta needed to constantly empty your hand for another Necronomicon charge, but it's by no means necessary.
Fractalling pretty much anything will make this somewhat OP, actually, not just 0-cost creatures.
On another note, what if you sacrifice a Phoenix? Does it come back as ash?