Demogorgon, Prince of Demons

In addition to its other costs sacrifice five
creatures and pay {p/b}{p/b}{p/b}{p/b}{p/b}{p/b}{p/b}{p/b}{p/b}{p/b}.
You may sacrifice a creature to Demogorgon at
any time.
Whenever you sacrifice a creature add {b} to your
mana pool.
Whenever you sacrifice a creature deal damage
equal to its toughness to any target.
Demogorgon can only attack if you sacrificed a creature this turn.