Mrolgath, King of Demons

Mrolgath, King of Demons costs {1} less to cast
for each demon you control.
When Mrolgath enters the battlefield, target
player loses one life for each demon and contract
you control, then creatures you control get +1/+1
and gain haste and deathtouch until end of turn.
{4}{b}{r}{g}, sacrifice two demons: Return Mrolgath
from your graveyard to the battlefield
tapped.