Karthus, the Deathsinger

Undying
Whenever a creature you control dies, you gain
2 life.
Whenever a creature an opponent controls dies,
they lose 2 life.
Torment-{b}{b}, Exile two other creature cards
from your graveyard: Return Karthus, the Deathsigner from your graveyard to the
battlefield. Then, each opponent loses life equal
to the number of creatures you own in exile.