Kozgach, Gravelord

Wither (This deals damage to creatures in the form
of -1/-1 counters.)
Black and red instant and sorcery spells you cast
have gravestorm. (When you cast this spell, copy it
for each permanent put into a graveyard this turn.)
At the beginning of your upkeep, sacrifice
another creature you control. If you can't,
sacrifice Kozgach.