Voidwalker

If a card would be put into an opponent's
graveyard from anywhere, instead exile it with a
void counter on it.
{1}, Sacrifice Voidwalker: Choose a card exiled
with Voidwalker with a void counter on it. You
may play that card this turn without paying its
mana cost.
"The void is hungry, and I am its willing servant.
Let your secrets slip, and they will be consumed."