Kerrigan, Queen of Blades

Swarm Supremacy - Other Zerg creatures you control get +1/+1 and have menace.
Psionic Overlord - Whenever a creature an opponent controls dies, you may pay {u}{b}. If you do, return it to the battlefield under your control as a black Zerg Horror with haste.
Evolve the Swarm - {2}{b}{g}, Sacrifice another creature: Put a number of +1/+1 counters on Kerrigan equal to the sacrificed creature’s power. If a non-Zerg was sacrificed this way, create two 1/1 black Zerg creature tokens.