Ruinous Waterbending (118) - Avatar: The Last Airbender

As an additional cost to cast this spell, you may waterbend 4. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for 1.)

All creatures get -2/-2 until end of turn. If this spell's additional cost was paid, whenever a creature dies this turn, you gain 1 life.