Demrgan, Demon of Descent

Descend (If there are eight or more creature cards in
your graveyard, you get the crypt's blessing for the
rest of the game.)
Flying
Whenever a permanent card is put into a
graveyard from anywhere for the first or second
time each turn, each player mills a card. Then if
you have the crypt's blessing, each opponent
loses 1 life.