Ruinous Waterbending [Avatar: The Last Airbender]

Description

Set:	Avatar: The Last Airbender
Type:	Sorcery — Lesson
Rarity:	Uncommon
Cost:	{1}{B}{B}

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.