Death's Sacrifice

Enchant Black Creature
At the beginning of each players upkeep
and end step, you may sacrifice a creature.
If you do, Scry 2 and draw a card.
If the sacrificed creature's power is 3 or less,
target player exiles the top 4 cards of their library.
If the sacrificed creature's power is 4 or greater,
you gain 5 life.