Sphilth, the Soul Warden

Whenever a creature dies, return that creature to the battlefield under your control with two Decay counters on it. It becomes a zombie in addition to
its other types. (At the beginning of your upkeep remove a decay counter from this creature. If there
are no decay counters remaining, return this card
to its owners graveyard.)
Zombies you control have fear
{x}, sacrifice X zombies: Lose X life, draw cards
equal to half X rounded up.