Shadow Man, The Corrupted

Flying, Haste, protection from non-permanents
When this creature enters the battlefield, Each
player sacrifices a creature. Your opponents lose
X life, where X is the highest sacrificed creature's
converted mana cost times the amount of players affected by this ability.
You may exert Shadow Man as it attacks. If you
do, it gets +5/+6 and trample until end of turn.