Karthus, The Harbinger

Wither (This deals damage to creatures in the
form of -1/-1 counters.)
If Karthus, The Harbinger enters the battlefield
from the graveyard, destroy all creatures.
Unearth {b}{b}{b}{b}{b} ({b}{b}{b}{b}{b}: Return this
card from your graveyard to the battlefield. It gains
haste. Exile it at the beginning of the next end step or
if it would leave the battlefield.