Voshyx, Devourer of Sanity

Degenerate 5 (At the beginning of your upkeep, sacrifice this creature unless you remove five cards from among graveyards.)
Whenever you exile a card from your graveyard, each opponent puts that many cards from the top of his or her library into his or her graveyard.
When the feeding ends, he will eventually turn to himself to sustain his gluttony.