The Forbidden Grave Site

Whenever a creature is exiled from a graveyard,
put tomb counter on it.
{t}: Exile target creature from a graveyard.
Create a 2/2 zombie with Decayed.
{8}, {t}, Sacrifice The Forbidden Grave Site:
Return all creatures with tomb counters to the battlefield under your control, they are black
zombies in addition to their other types.