I'm sorry if there's already a thread on this, I've got to stop being lazy. Anyway, on the card "Goblin Cleaver" it is a combat action, and you can only do combat actions after the shadow cards have been dealt. So if goblin cleaver took out the enemy, what would happen to that enemy's shadow card? I'm guessing you just discard it, because since there's no enemy you can't resolve the attack. But just to make sure, it wouldn't go back on top of the deck, right?

Discard the shadow card along with the enemy you just defeated.

Okay thanks for the information!