Karras, The Fallen

Flash, Flying, Haunt.
When Karras, The Fallen, enters play (or
creature it Haunts dies) all black creatures
get +2/+2 until end of turn.
{t},{4}; Sacrifice a creature. Destroy target Demon.
Gain life equal to sacrificed creatures' converted
mana cost.
"Do you wish to repent your sins Karras?"