Stygian Skull

When Stygian Skull enters the battlefield each opponent loses 3 life and you gain 3 life.
Whenever you cast a black spell, you may exile
Stygian Skull with three time counters on it and
it gains suspend. (Exile it with three time counters
on it. At the beginning of your upkeep, remove a time
counter. When the last is removed, cast it without
paying its mana cost.)