Greater Good

Sacrifice a creature: Draw cards equal to the sacrificed creature's power, then discard three cards.

Damnation

Destroy all creatures. They can't be regenerated.

Essence Warden

Whenever another creature enters, you gain 1 life.

Savra, Queen of the Golgari

Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature of their choice.
Whenever you sacrifice a green creature, you may gain 2 life.