Arjai, Perches of Freedom

{t}: Add {w}, {u}, or {r}
Arjai, Perches of Freedom isn't a spell.
You may choose to pay it's mana cost.
Arjai, Perches of Freedom enters the battlefield
tapped. If you paid it's mana cost, Gust 2
(Until end of turn whenever a creature you control
with flying enters the battlefield, you gain 2 life.)