Thalakos Seer

Shadow (This creature can block or be blocked by only creatures with shadow.)
When Thalakos Seer leaves the battlefield, draw a card.

Saprazzan Bailiff

When Saprazzan Bailiff enters, exile all artifact and enchantment cards from all graveyards.
When Saprazzan Bailiff leaves the battlefield, return all artifact and enchantment cards from all graveyards to their owners' hands.

Servant of Volrath

When Servant of Volrath leaves the battlefield, sacrifice a creature.