Great Divide Guide

Each land and Ally you control has "{T}: Add one mana of any color."

Aang and Katara

Whenever Aang and Katara enter or attack, create X 1/1 white Ally creature tokens, where X is the number of tapped artifacts and/or creatures you control.

Hermitic Herbalist

{T}: Add one mana of any color.
{T}: Add two mana in any combination of colors. Spend this mana only to cast Lesson spells.

Katara, the Fearless

If a triggered ability of an Ally you control triggers, that ability triggers an additional time.

Aang and La, Ocean's Fury

Reach, trample
Whenever Aang and La attack, put a +1/+1 counter on each tapped creature you control.

Aang, Swift Savior

Flash
Flying
When Aang enters, airbend up to one other target creature or spell. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Waterbend {8}: Transform Aang.