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.

Weapons Trainer

Other creatures you control get +1/+0 as long as you control an Equipment.

Raugrin Triome

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

Fated Firepower

Flash
This enchantment enters with X fire counters on it.
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus an amount of damage equal to the number of fire counters on this enchantment instead.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

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.

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.

Gran-Gran

Whenever Gran-Gran becomes tapped, draw a card, then discard a card.
Noncreature spells you cast cost {1} less to cast as long as there are three or more Lesson cards in your graveyard.

Akroma's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Creatures you control gain flying, vigilance, and double strike until end of turn.
• Creatures you control gain lifelink, indestructible, and protection from each color until end of turn.

Deserted Beach

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

Sol Ring

Arcane Signet

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

Secret of Bloodbending

As an additional cost to cast this spell, you may waterbend {10}.
You control target opponent during their next combat phase. If this spell's additional cost was paid, you control that player during their next turn instead. (You see all cards that player could see and make all decisions for them.)
Exile Secret of Bloodbending.

The Mechanist, Aerial Artisan

Whenever you cast a noncreature spell, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{T}: Until end of turn, target artifact token you control becomes a 3/1 Construct artifact creature with flying.

Yue, the Moon Spirit

Flying, vigilance
Waterbend {5}, {T}: You may cast a noncreature spell from your hand without paying its mana cost.

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.

It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Port Town

As this land enters, you may reveal a Plains or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {U}.

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.

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.

Stormcarved Coast

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

Evolving Wilds

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

Loyal Fire Sage

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
{5}: Create a 1/1 white Ally creature token.

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Perilous Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Island, Mountain, or Plains card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{R}{W} ({U}{R}{W}, Discard this card: Draw a card.)

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.

Lantern Scout

Rally — Whenever this creature or another Ally you control enters, creatures you control gain lifelink until end of turn.

Ondu Cleric

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

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.)

Counterspell

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.

Trusty Boomerang

Equipped creature has "{1}, {T}: Tap target creature. Return Trusty Boomerang to its owner's hand."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

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

Clifftop Retreat

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

Diamond Pick-Axe

Indestructible (Effects that say "destroy" don't destroy this Equipment.)
Equipped creature gets +1/+1 and has "Whenever this creature attacks, create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Equip {2}

Iroh, Firebending Instructor

Whenever Iroh attacks, attacking creatures get +1/+1 until end of turn.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Mountain

Swords to Plowshares

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

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Command Tower

Katara, Waterbending Master

Whenever you cast a spell during an opponent's turn, you get an experience counter.
Whenever Katara attacks, you may draw a card for each experience counter you have. If you do, discard a card.

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.

United Front

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

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.

How to Start a Riot

Target creature gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Creatures target player controls get +2/+0 until end of turn.

Mystic Monastery

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

Akoum Battlesinger

Haste
Whenever this creature or another Ally you control enters, you may have Ally creatures you control get +1/+0 until end of turn.

Stone Haven Outfitter

Equipped creatures you control get +1/+1.
Whenever an equipped creature you control dies, draw a card.

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}.)

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.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Mechanical Glider

When this Equipment enters, attach it to target creature you control.
Equipped creature has flying. (It can't be blocked except by creatures with flying or reach.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Avatar Enthusiasts

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

Prairie Stream

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

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Sulfur Falls

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

Katara, Bending Prodigy

At the beginning of your end step, if Katara is tapped, put a +1/+1 counter on her.
Waterbend {6}: Draw a card. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Furycalm Snarl

As this land enters, you may reveal a Mountain or Plains card from your hand. If you don't, this land enters tapped.
{T}: Add {R} or {W}.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Plains

Island

Jeskai Charm

Choose one —
• Put target creature on top of its owner's library.
• Jeskai Charm deals 4 damage to target opponent or planeswalker.
• Creatures you control get +1/+1 and gain lifelink until end of turn.

Glacial Fortress

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

Hero of Goma Fada

Rally — Whenever this creature or another Ally you control enters, creatures you control gain indestructible until end of turn.

Seachrome Coast

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

Resourceful Defense

Whenever a permanent you control leaves the battlefield, if it had counters on it, put those counters on target permanent you control.
{4}{W}: Move any number of counters from target permanent you control to another target permanent you control.

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.

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.)

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. This land deals 1 damage to you.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

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

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

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.

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. This artifact deals 1 damage to you.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.