I'm not quite sure what this is meant to mean. Were you going for

> Whenever you pay life to cast a spell or activate an ability, you may draw a card

?

It's an Aura that attaches to Wall of Blood, turning it into Yawgmoth's Bargain.

Or Mischievous Poltergeist. But hey, let's be frank, those cards could use the help.

This is rather nice beside Erebos, God of the Dead. Not only does it provide nearly all the devotion you need, but it gives his ability a rather better rate of return.

Also spectacular in a Phyrexian-mana deck, which I imagine is the point. Spellskite is suddenly extremely scary.

Perhaps this should be rare then?

Mmm. Depends on the set. It'd certainly look fine at rare.

If this were going to stay at uncommon, I'd suggest changing the cost from to . "A black enchantment costing " is a category that people expect to be rare :)