Natalia Romanoff, Black Widow

{t}, Sacrifice another creatur: If the creature was black, search you library for a soldier or assassin with mana cost X or less, where X is the sacrificed creatures mana cost. Put that creature on the battlefield. If the creature was red, deal X damage to target creature, where X is the sacrificed creature's power.

Whenever a creature you control dies, put an ultimate counter on Natalia Romanoff, Black Widow. If Natalia Romanoff, Black Widow has 5 ultimate counters, remove her from battlefield and ret