Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Avatar's Wrath

Choose up to one target creature, then airbend all other creatures. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Until your next turn, your opponents can't cast spells from anywhere other than their hands.
Exile Avatar's Wrath.

Aang, Master of Elements

Flying
Spells you cast cost {W}{U}{B}{R}{G} less to cast. (This can reduce generic costs.)
At the beginning of each upkeep, you may transform Aang, Master of Elements. If you do, you gain 4 life, draw four cards, put four +1/+1 counters on him, and he deals 4 damage to each opponent.

Avatar Aang

Flying, firebending 2
Whenever you waterbend, earthbend, firebend, or airbend, draw a card. Then if you've done all four this turn, transform Avatar Aang.

Avatar Aang // Aang, Master of Elements

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Great Divide Guide

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

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Katara, the Fearless

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

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Arcane Signet

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.