Aang, The Last Airbender

When Aang, The Last Airbender enters the battlefield, draw a card.
Landfall--Whenever a land enters the battlefield under your control, you gain 4 life if this is the first time this ability has resolved this turn.If it's the second time, add{u}{g}{r}{w}. If it's the third time, Aang deals 4 damage to each opponent and each planeswalker you don't control.