Vana, Voice of the Essence

Flying, Lifelink
{1}{p/b}{p/w}: Switch between Light and Dark. (Any player may activate this ability.)
Light: All creatures gain +1/+1 until end of turn.
Dark: All creatures gain -1/-1 until end of turn.
"Vana vowed to fight for the ultimate balance, and spend her whole life for the cause of the Essence."