Chest of Souls

Whenever a creature would be put into the
graveyard from anywhere, put it into exile. Put a
soul counter of Chest of Souls
{x}{4}{t} Remove a soul
counter from Chest Of Souls; return target
creature from
exile onto the battlefield under your control,
where X is target creature's mana cost. Target creature is a black Spirit in addition to its other
colors and types.