I think your sleep function is OP'd. The only way to wake up a creature is to damage it? You could do this to all your opponent's creatures and they would have to spend all their CC waking up their own creatures.
um... Similarities? (http://elementscommunity.org/forum/index.php/topic,25063.0.html)
Poison could be interesting with this card...I hadn't thought about that. Requires a trio to work, but it would be fun. Kind of like Meat Wagon actually.