Path to Redemption

Enchant creature
Enchanted creature can't attack or block.
{5}, Sacrifice this Aura: Exile enchanted creature. Create a 1/1 white Ally creature token. Activate only during your turn.

Sokka, Lateral Strategist

Vigilance
Whenever Sokka and at least one other creature attack, draw a card.

Trapped in the Screen

Ward {2} (Whenever this enchantment becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When this enchantment enters, exile target artifact, creature, or enchantment an opponent controls until this enchantment leaves the battlefield.

Invasion Reinforcements

Flash
When this creature enters, create a 1/1 white Ally creature token.

Momo, Playful Pet

Flying, vigilance
When Momo leaves the battlefield, choose one —
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
• Put a +1/+1 counter on target creature you control.
• Scry 2.

Hakoda, Selfless Commander

Vigilance
You may look at the top card of your library any time.
You may cast Ally spells from the top of your library.
Sacrifice Hakoda: Creatures you control get +0/+5 and gain indestructible until end of turn.

Fancy Footwork

Untap one or two target creatures. They each get +2/+2 until end of turn.

South Pole Voyager

Whenever this creature or another Ally you control enters, you gain 1 life. If this is the second time this ability has resolved this turn, draw a card.

Avatar Enthusiasts

Whenever another Ally you control enters, put a +1/+1 counter on this creature.

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.

Aang, Swift Savior // Aang and La, Ocean's Fury

Jasmine Dragon Tea Shop

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Ally spell or activate an ability of an Ally source.
{5}, {T}: Create a 1/1 white Ally creature token.

Plains

Abandoned Air Temple

This land enters tapped unless you control a basic land.
{T}: Add {W}.
{3}{W}, {T}: Put a +1/+1 counter on each creature you control.

Yip Yip!

Target creature you control gets +2/+2 until end of turn. If that creature is an Ally, it also gains flying until end of turn.

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Earth Kingdom Protectors

Vigilance
Sacrifice this creature: Another target Ally you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)