Bender's Waterskin

Untap this artifact during each other player's untap step.
{T}: Add one mana of any color.

Aang, Airbending Master

When Aang enters, airbend another target creature. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.
At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.

Sunpetal Grove

This land enters tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Appa, the Vigilant

Flying, vigilance
Whenever Appa or another Ally you control enters, creatures you control get +1/+1 and gain flying and vigilance until end of turn.

Hada Freeblade

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

Sol Ring

Herald's Horn

As this artifact enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Aang, Destined Savior

Flying
Land creatures you control have vigilance.
At the beginning of combat on your turn, earthbend 2. (Target land you control becomes a 0/0 creature with haste that's still a land. Put two +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Aang, at the Crossroads

Flying
When Aang enters, look at the top five cards of your library. You may put a creature card with mana value 4 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
When another creature you control leaves the battlefield, transform Aang at the beginning of the next upkeep.

Aang, at the Crossroads // Aang, Destined Savior

Jwari Shapeshifter

You may have this creature enter as a copy of any Ally creature on the battlefield.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Reflections of Littjara

As this enchantment enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Seaside Citadel

This land enters tapped.
{T}: Add {G}, {W}, or {U}.

Waterbender Ascension

Whenever a creature you control deals combat damage to a player, put a quest counter on this enchantment. Then if it has four or more quest counters on it, draw a card.
Waterbend {4}: Target creature can't be blocked this turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Temple Garden

({T}: Add {G} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Kindred Discovery

As this enchantment enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Sokka's Charge

During your turn, Allies you control have double strike and lifelink.

Kazandu Blademaster

First strike, vigilance
Whenever this creature or another Ally you control enters, you may put a +1/+1 counter on this creature.

Arcane Signet

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

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

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.

It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Earth King's Lieutenant

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

Farseek

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

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Forest

Counterspell

Avatar Enthusiasts

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

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.

Invasion Reinforcements

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

Master Piandao

First strike
Whenever Master Piandao attacks, look at the top four cards of your library. You may reveal an Ally, Equipment, or Lesson card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Plains

Tale of Katara and Toph

Creatures you control have "Whenever this creature becomes tapped for the first time during each of your turns, put a +1/+1 counter on it."

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Ty Lee, Chi Blocker

Flash
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Ty Lee enters, tap up to one target creature. It doesn't untap during its controller's untap step for as long as you control Ty Lee.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Allied Teamwork

When this enchantment enters, create a 1/1 white Ally creature token.
Allies you control get +1/+1.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

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.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Allies at Last

Affinity for Allies (This spell costs {1} less to cast for each Ally you control.)
Up to two target creatures you control each deal damage equal to their power to target creature an opponent controls.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Origin of Metalbending

Choose one —
• Destroy target artifact or enchantment.
• Put a +1/+1 counter on target creature you control. It gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Ally Encampment

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Ally spell.
{1}, {T}, Sacrifice this land: Return target Ally you control to its owner's hand.

Airbender Ascension

When this enchantment enters, airbend up to one target creature.
Whenever a creature you control enters, put a quest counter on this enchantment.
At the beginning of your end step, if this enchantment has four or more quest counters on it, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Haru, Hidden Talent

Whenever another Ally you control enters, earthbend 1. (Target land you control becomes a 0/0 creature with haste that's still a land. Put a +1/+1 counter on it. When it dies or is exiled, return it to the battlefield tapped.)

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

Secret Tunnel

This land can't be blocked.
{T}: Add {C}.
{4}, {T}: Two target creatures you control that share a creature type can't be blocked this turn.

Suki, Kyoshi Warrior

Suki's power is equal to the number of creatures you control.
Whenever Suki attacks, create a 1/1 white Ally creature token that's tapped and attacking.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Command Tower

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.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Swords to Plowshares

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

Sokka, Lateral Strategist

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

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

United Front

Create X 1/1 white Ally creature tokens, then put a +1/+1 counter on each creature you control.

White Lotus Reinforcements

Vigilance
Other Allies you control get +1/+1.

Turntimber Ranger

Whenever this creature or another Ally you control enters, you may create a 2/2 green Wolf creature token. If you do, put a +1/+1 counter on this creature.

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Kabira Evangel

Whenever this creature or another Ally you control enters, you may choose a color. If you do, Allies you control gain protection from the chosen color until end of turn.

Rejuvenating Springs

This land enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Appa, Steadfast Guardian

Flash
Flying
When Appa enters, airbend any number of other target nonland permanents you control. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever you cast a spell from exile, create a 1/1 white Ally creature token.

Shared Roots

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Island

The Earth King

When The Earth King enters, create a 4/4 green Bear creature token.
Whenever one or more creatures you control with power 4 or greater attack, search your library for up to that many basic land cards, put them onto the battlefield tapped, then shuffle.

Great Divide Guide

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

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.)

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

White Lotus Tile

This artifact enters tapped.
{T}: Add X mana of any one color, where X is the greatest number of creatures you control that have a creature type in common.

Ondu Cleric

Whenever this creature or another Ally you control enters, you may gain life equal to the number of Allies you control.

Katara, Water Tribe's Hope

Vigilance
When Katara enters, create a 1/1 white Ally creature token.
Waterbend {X}: Creatures you control have base power and toughness X/X until end of turn. X can't be 0. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Earth Kingdom Jailer

When this creature enters, exile up to one target artifact, creature, or enchantment an opponent controls with mana value 3 or greater until this creature leaves the battlefield.

Urza's Incubator

As this artifact enters, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Harabaz Druid

{T}: Add X mana of any one color, where X is the number of Allies you control.

Talus Paladin

Whenever this creature or another Ally you control enters, you may have Allies you control gain lifelink until end of turn, and you may put a +1/+1 counter on this creature.

Sea Gate Loremaster

{T}: Draw a card for each Ally you control.

Katara, the Fearless

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

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.