Aang, The Last Airbender

Flying, Vigilance, Lifelink
When you cast your first white, green, or blue
spell per turn, put a +1/+1 counter on each
creature you control. Creatures you control
have hexproof. Whenever a creature you
control deals combat damage to a player,
draw a card.
(Transformed Aang, Airbender)
The avatar state is the ultimate weapon,
you just need to control it.