Bul-Tsar, Corpse-Basher

If you've milled 5 or more cards this turn,
Bul-Tsar, Corpse-Basher gains flying, and indestructible till the end of turn.
{6}, Sacrifice a creature you control:
Scry 2, draw 2, and mill 2 cards.
"Pain and suffering is music to my ears."