Oralia, the Soulless

Bloodthirst 4 (If an opponent was dealt damage this
turn, this permanent enters the battlefield with four
+1/+1 counters on it.)
Whenever you cast a creature spell, it gains bloodthirst X, where X is it converted mana cost.
{3}{b}{r}{g}: You sacrifice a creature. Oralia, the Soulless deals damage to target creature or player
equal to the converted mana cost of the creature sacrificed this way.