Katara, Bloodbending Savant

Vigilance
{1}{b}, pay 1 life: Target creature an opponent controls gets -3/-1 until end of turn.
{1}{w}{b}, pay 3 life: Creatures your opponents
control gets -2/-1 until end of turn.
{3}{w/b}{w/b}, pay 5 life: Creatures your opponents
control get -4/-1 as long as Katara, Bloodbending Savant is on the battlefield.