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.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Spellseeker

When this creature enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

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.)

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Nimbus Maze

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

Island

Airbending Lesson

Airbend target nonland permanent. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Draw a card.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Floodfarm Verge

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

Reliquary Tower

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

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Command Tower

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

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

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.)

Tui and La, Moon and Ocean

Whenever Tui and La become tapped, draw a card.
Whenever Tui and La become untapped, put a +1/+1 counter on them.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Aang's Iceberg

Flash
When this enchantment enters, exile up to one other target nonland permanent until this enchantment leaves the battlefield.
Waterbend {3}: Sacrifice this enchantment. If you do, scry 2. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

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.

Claim Jumper

Vigilance
When this creature enters, if an opponent controls more lands than you, you may search your library for a Plains card and put it onto the battlefield tapped. Then if an opponent controls more lands than you, repeat this process once. If you search your library this way, shuffle.

Plains

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Pearl Medallion

White spells you cast cost {1} less to cast.

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.

Prairie Stream

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

Suki, Courageous Rescuer

Other creatures you control get +1/+0.
Whenever another permanent you control leaves the battlefield during your turn, create a 1/1 white Ally creature token. This ability triggers only once each turn.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Helm of Awakening

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Cloudblazer

Flying
When this creature enters, you gain 2 life and draw two cards.

Generous Gift

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

Recruiter of the Guard

When this creature enters, you may search your library for a creature card with toughness 2 or less, reveal it, put it into your hand, then shuffle.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

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.

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.

Hydroelectric Laboratory

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

Circuit Mender

When this creature enters, you gain 2 life.
When this creature leaves the battlefield, draw a card.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

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.

White Plume Adventurer

When this creature enters, you take the initiative.
At the beginning of each opponent's upkeep, untap a creature you control. If you've completed a dungeon, untap all creatures you control instead.

Anticausal Vestige

When this creature leaves the battlefield, draw a card, then you may put a permanent card with mana value less than or equal to the number of lands you control from your hand onto the battlefield tapped.
Warp {4} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Katara, Heroic Healer

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Katara enters, put a +1/+1 counter on each other creature you control.

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.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Mnemonic Wall

Defender
When this creature enters, you may return target instant or sorcery card from your graveyard to your hand.

Ghostly Prison

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

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

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}.)

Tribute Mage

When this creature enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Aven Interrupter

Flash
Flying
When this creature enters, exile target spell. It becomes plotted. (Its owner may cast it as a sorcery on a later turn without paying its mana cost.)
Spells your opponents cast from graveyards or from exile cost {2} more to cast.

Enter the Avatar State

Until end of turn, target creature you control becomes an Avatar in addition to its other types and gains flying, first strike, lifelink, and hexproof. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

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.

Swords to Plowshares

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

Aether Channeler

When this creature enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Starfield Vocalist

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Warp {1}{U} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

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.

Sol Ring

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Windbrisk Heights

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Glacial Fortress

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

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Sea of Clouds

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

Witch-Blessed Meadow

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {W}.

Witch Enchanter

When this creature enters, destroy target artifact or enchantment an opponent controls.

Witch Enchanter // Witch-Blessed Meadow

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on this creature.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Hallowed Fountain

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

Restoration Angel

Flash
Flying
When this creature enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Moonshaker Cavalry

Flying
When this creature enters, creatures you control gain flying and get +X/+X until end of turn, where X is the number of creatures you control.

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.)

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Tundra

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Arcane Signet

Appa, Loyal Sky Bison

Flying
Whenever Appa enters or attacks, choose one —
• Target creature you control gains flying until end of turn.
• Airbend another target nonland permanent you control. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)