Katara, Warrior and Healer

Lifelink, vigilance

Whenever a land that can produce {u} enters the battlefield under your control, you may play a creature
from your graveyard or regenerate target creature.

You may play an additional land card that can produce {u} from your graveyard or your hand during your turn.

"Give me one reason to think that you might hurt Aang,
and I'll make sure your destiny ends, right then and there, permanently."