Have

Woodland Cemetery

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

Cycle of Renewal

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Airbender's Reversal

Choose one —
• Destroy target attacking creature.
• Airbend target creature you control. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)

Dai Li Agents

When this creature enters, earthbend 1, then earthbend 1. (To 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.)
Whenever this creature attacks, each opponent loses X life and you gain X life, where X is the number of creatures you control with +1/+1 counters on them.

Maybe

Invasion Submersible

When this Vehicle enters, return up to one other target nonland permanent to its owner's hand.
Exhaust — Waterbend {3}: This Vehicle becomes an artifact creature. Put three +1/+1 counters on it. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}. Activate each exhaust ability only once.)

Spirit Water Revival

As an additional cost to cast this spell, you may waterbend {6}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Draw two cards. If this spell's additional cost was paid, instead shuffle your graveyard into your library, draw seven cards, and you have no maximum hand size for the rest of the game.
Exile Spirit Water Revival.

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.

Toph, the First Metalbender

Nontoken artifacts you control are lands in addition to their other types. (They don't gain the ability to {T} for mana.)
At the beginning of your end step, 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.)

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}.)

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.)

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}.)

Ally

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.

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Toph, Greatest Earthbender

When Toph enters, earthbend X, where X is the amount of mana spent to cast her.
Land creatures you control have double strike.

Avatar Kyoshi, Earthbender

During your turn, Avatar Kyoshi has hexproof.
At the beginning of combat on your turn, earthbend 8, then untap that land. (Target land you control becomes a 0/0 creature with haste that's still a land. Put eight +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Ozai, the Phoenix King

Trample, firebending 4, haste
If you would lose unspent mana, that mana becomes red instead.
Ozai has flying and indestructible as long as you have six or more unspent mana.

Getting

Urza's Cave

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Hog-Monkey Rampage

Choose target creature you control and target creature an opponent controls. Put a +1/+1 counter on the creature you control if it has power 4 or greater. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Monk Gyatso

Whenever another creature you control becomes the target of a spell or ability, you may airbend that creature. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)

Fist of Suns

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

The Last Agni Kai

Target creature you control fights target creature an opponent controls. If the creature the opponent controls is dealt excess damage this way, add that much {R}.
Until end of turn, you don't lose unspent red mana as steps and phases end.

Water Tribe Rallier

Waterbend {5}: Look at the top four cards of your library. You may reveal a creature card with power 3 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

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.

Soldier

Firebending 1 (Whenever this token attacks, add {R}. This mana lasts until end of combat.)

Sun Warriors

Firebending X, where X is the number of creatures you control. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)
{5}: Create a 1/1 white Ally creature token.

Invasion Tactics

When this enchantment enters, creatures you control get +2/+2 until end of turn.
Whenever one or more Allies you control deal combat damage to a player, draw a card.

Jungle Shrine

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

Sol Ring

Foggy Swamp Visions

As an additional cost to cast this spell, waterbend {X}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Exile X target creature cards from graveyards. For each creature card exiled this way, create a token that's a copy of it. At the beginning of your next end step, sacrifice those tokens.

Harabaz Druid

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

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Avatar Yangchen

Flying
Whenever you cast your second spell each turn, airbend up to one other target nonland permanent. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)

The Legend of Yangchen

(As this Saga enters and after your draw step, add a lore counter.)
I — Starting with you, each player chooses up to one permanent with mana value 3 or greater from among permanents your opponents control. Exile those permanents.
II — You may have target opponent draw three cards. If you do, draw three cards.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Yangchen // Avatar Yangchen

Earthen Ally

This creature gets +1/+0 for each color among Allies you control.
{2}{W}{U}{B}{R}{G}: Earthbend 5. (Target land you control becomes a 0/0 creature with haste that's still a land. Put five +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Kodama's Reach

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.

Forest

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Avatar Kuruk

Whenever you cast a spell, create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."
Exhaust — Waterbend {20}: Take an extra turn after this one. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}. Activate each exhaust ability only once.)

The Legend of Kuruk

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Scry 2, then draw a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Kuruk // Avatar Kuruk

Ruinous Waterbending

As an additional cost to cast this spell, you may waterbend {4}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
All creatures get -2/-2 until end of turn. If this spell's additional cost was paid, whenever a creature dies this turn, you gain 1 life.

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Arcane Signet

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

Octopus Form

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Maelstrom Nexus

The first spell you cast each turn has cascade. (When you cast your first spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Fire Lord Zuko

Firebending X, where X is Fire Lord Zuko's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)
Whenever you cast a spell from exile and whenever a permanent you control enters from exile, put a +1/+1 counter on each creature you control.

Great Divide Guide

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

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.

Great Hall of the Citadel

{T}: Add {C}.
{1}, {T}: Add two mana in any combination of colors. Spend this mana only to cast legendary spells.

Fatal Fissure

Choose target creature. When that creature dies this turn, you earthbend 4. (Target land you control becomes a 0/0 creature with haste that's still a land. Put four +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Firebending Student

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Firebending X, where X is this creature's power. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)

Avatar Roku

Firebending 4 (Whenever this creature attacks, add {R}{R}{R}{R}. This mana lasts until end of combat.)
{8}: Create a 4/4 red Dragon creature token with flying and firebending 4.

The Legend of Roku

(As this Saga enters and after your draw step, add a lore counter.)
I — Exile the top three cards of your library. Until the end of your next turn, you may play those cards.
II — Add one mana of any color.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Roku // Avatar Roku

Katara, the Fearless

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

Chromatic Lantern

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

Plains

Sozin's Comet

Each creature you control gains firebending 5 until end of turn. (Whenever it attacks, add {R}{R}{R}{R}{R}. This mana lasts until end of combat.)
Foretell {2}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Fire Nation Palace

This land enters tapped unless you control a basic land.
{T}: Add {R}.
{1}{R}, {T}: Target creature you control gains firebending 4 until end of turn. (Whenever it attacks, add {R}{R}{R}{R}. This mana lasts until end of combat.)

Aang, the Last Airbender

Flying
When Aang enters, airbend up to one other target nonland permanent. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever you cast a Lesson spell, Aang gains lifelink until end of turn.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Command Tower

Bitter Work

Whenever you attack a player with one or more creatures with power 4 or greater, draw a card.
Exhaust — {4}: Earthbend 4. Activate only during your turn. (Target land you control becomes a 0/0 creature with haste that's still a land. Put four +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped. Activate each exhaust ability only once.)

Earthshape

Earthbend 3. Then each creature you control with power less than or equal to that land's power gains hexproof and indestructible until end of turn. You gain hexproof until end of turn.

Avatar Kyoshi

Lands you control have trample and hexproof.
{T}: Add X mana of any one color, where X is the greatest power among creatures you control.

The Legend of Kyoshi

(As this Saga enters and after your draw step, add a lore counter.)
I — Draw cards equal to the greatest power among creatures you control.
II — Earthbend X, where X is the number of cards in your hand. That land becomes an Island in addition to its other types.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Kyoshi // Avatar Kyoshi

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.

Seaside Citadel

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

Boiling Rock Rioter

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Tap an untapped Ally you control: Exile target card from a graveyard.
Whenever this creature attacks, you may cast an Ally spell from among cards you own exiled with this creature.

Sokka, Tenacious Tactician

Menace, prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Other Allies you control have menace and prowess.
Whenever you cast a noncreature spell, create a 1/1 white Ally creature token.

Energybending

Lands you control gain all basic land types until end of turn.
Draw a card.

Reliquary Tower

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

Rumble Arena

Vigilance
When this land enters, scry 1. (Look at the top card of your library. You may put it on the bottom.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

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.)

Earthbender Ascension

When this enchantment enters, earthbend 2. Then search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, put a quest counter on this enchantment. When you do, if it has four or more quest counters on it, put a +1/+1 counter on target creature you control. It gains trample until end of turn.

Hinterland Harbor

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

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Cinder Glade

({T}: Add {R} or {G}.)
This land enters tapped unless you control two or more basic lands.

Zuko, Firebending Master

First strike
Firebending X, where X is the number of experience counters you have. (Whenever this creature attacks, add X {R}. This mana lasts until end of combat.)
Whenever you cast a spell during combat, you get an experience counter.

Uncle Iroh

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Lesson spells you cast cost {1} less to cast.

Bender's Waterskin

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

Redirect Lightning

As an additional cost to cast this spell, pay 5 life or pay {2}.
Change the target of target spell or ability with a single target.

Iroh, Grand Lotus

Firebending 2
During your turn, each non-Lesson instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost. (You may cast a card from your graveyard for its flashback cost. Then exile it.)
During your turn, each Lesson card in your graveyard has flashback {1}.

The Boulder, Ready to Rumble

Whenever The Boulder attacks, earthbend X, where X is the number of creatures you control with power 4 or greater. (Target land you control becomes a 0/0 creature with haste that's still a land. Put X +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

March from the Tomb

Return any number of target Ally creature cards with total mana value 8 or less from your graveyard to the battlefield.

Waterbender's Restoration

As an additional cost to cast this spell, waterbend {X}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Exile X target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

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.)

Dai Li Indoctrination

Choose one —
• Target opponent reveals their hand. You choose a nonland permanent card from it. That player discards that card.
• 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.)

Elemental Teachings

Search your library for up to four land cards with different names and reveal them. An opponent chooses two of those cards. Put the chosen cards into your graveyard and the rest onto the battlefield tapped, then shuffle.

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.

Sandsteppe Citadel

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

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Obscuring Haze

If you control a commander, you may cast this spell without paying its mana cost.
Prevent all damage that would be dealt this turn by creatures your opponents control.

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.

Horizon of Progress

{T}, Pay 1 life: Add one mana of any type that a land you control could produce.
{3}, {T}: You may put a land card from your hand onto the battlefield tapped.
{1}, {T}, Sacrifice this land: Draw a card.

North Pole Patrol

{T}: Untap another target permanent you control.
Waterbend {3}, {T}: Tap target creature an opponent controls. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Abandon Attachments

You may discard a card. If you do, draw two cards.

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.)