Nyla, Shirshu Sleuth

When Nyla enters, exile up to one target creature card from your graveyard. If you do, you lose X life and create X Clue tokens, where X is that card's mana value. (A Clue token is an artifact with "{2}, Sacrifice this token: Draw a card.")
At the beginning of your end step, if you control no Clues, return target card exiled with Nyla to its owner's hand.

Fire Lord Azula

Firebending 2 (Whenever this creature attacks, add {R}{R}. This mana lasts until end of combat.)
Whenever you cast a spell while Fire Lord Azula is attacking, copy that spell. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

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.)

Diaochan, Artful Beauty

{T}: Destroy target creature of your choice, then destroy target creature of an opponent's choice. Activate only during your turn, before attackers are declared.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Fire Nation Attacks

Create two 2/2 red Soldier creature tokens with firebending 1. (Whenever a creature with firebending 1 attacks, add {R}. This mana lasts until end of combat.)
Flashback {8}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Fire Nation Occupation

When this enchantment enters, create a 2/2 red Soldier creature token with firebending 1. (Whenever it attacks, add {R}. This mana lasts until end of combat.)
Whenever you cast a spell during an opponent's turn, create a 2/2 red Soldier creature token with firebending 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.

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}.)

Bender's Waterskin

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

Sulfur Falls

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

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.

Desperate Plea

As an additional cost to cast this spell, sacrifice a creature.
Choose one or both —
• Return target creature card from your graveyard to the battlefield if its power is less than or equal to the sacrificed creature's power.
• Destroy target creature.

Day of Black Sun

Each creature with mana value X or less loses all abilities until end of turn. Destroy those creatures.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

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.

Firebender Ascension

When this enchantment enters, create a 2/2 red Soldier creature token with firebending 1.
Whenever a creature you control attacking causes a triggered ability of that creature to trigger, put a quest counter on this enchantment. Then if it has four or more quest counters on it, you may copy that ability. You may choose new targets for the copy.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Cascade Bluffs

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

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.)

Water Whip

As an additional cost to cast this spell, waterbend {5}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Return up to two target creatures to their owners' hands. Draw two cards.

Choked Estuary

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

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Combustion Technique

Combustion Technique deals damage equal to 2 plus the number of Lesson cards in your graveyard to target creature. If that creature would die this turn, exile it instead.

Drowned Catacomb

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

The Fire Nation Drill

Trample
When The Fire Nation Drill enters, you may tap it. When you do, destroy target creature with power 4 or less.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Crew 2

June, Bounty Hunter

June can't be blocked as long as you've drawn two or more cards this turn.
{1}, Sacrifice another creature: Create a Clue token. Activate only during your turn. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Cunning Maneuver

Target creature gets +3/+1 until end of turn.
Create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Mountain

Shipwreck Marsh

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

Haunted Ridge

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

Exotic Orchard

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

Mai, Jaded Edge

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Exhaust — {3}: Put a double strike counter on Mai. (Activate each exhaust ability only once.)

Watery Grasp

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Waterbend {5}: Enchanted creature's owner shuffles it into their library. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Smoldering Marsh

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

Arcane Signet

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

Katara, Seeking Revenge

As an additional cost to cast this spell, you may waterbend {2}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
When Katara enters, draw a card, then discard a card unless her additional cost was paid.
Katara gets +1/+1 for each Lesson card in your graveyard.

Frantic Search

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

Mai, Scornful Striker

First strike
Whenever a player casts a noncreature spell, they lose 2 life.

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.)

Swamp

Deadly Precision

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature.
Destroy target creature.

Stormcarved Coast

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

Brainstorm

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

Chromatic Lantern

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

Overwhelming Victory

Overwhelming Victory deals 5 damage to target creature. Each creature you control gains trample and gets +X/+0 until end of turn, where X is the amount of excess damage dealt this way.

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.

Fire Nation Engineer

Raid — At the beginning of your end step, if you attacked this turn, put a +1/+1 counter on another target creature or Vehicle you control.

Rogue's Passage

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

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Epic Downfall

Exile target creature with mana value 3 or greater.

Graven Cairns

{T}: Add {C}.
{B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

Ozai's Cruelty

Ozai's Cruelty deals 2 damage to target player. That player discards two cards.

Sunken Hollow

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

Fire Lord Ozai

Whenever Fire Lord Ozai attacks, you may sacrifice another creature. If you do, add an amount of {R} equal to the sacrificed creature's power. Until end of combat, you don't lose this mana as steps end.
{6}: Exile the top card of each opponent's library. Until end of turn, you may play one of those cards without paying its mana cost.

Azula, Cunning Usurper

Firebending 2 (Whenever this creature attacks, add {R}{R}. This mana lasts until end of combat.)
When Azula enters, target opponent exiles a nontoken creature they control, then they exile a nonland card from their graveyard.
During your turn, you may cast cards exiled with Azula and you may cast them as though they had flash. Mana of any type can be spent to cast those spells.

Fire Lord Sozin

Menace, firebending 3 (Whenever this creature attacks, add {R}{R}{R}. This mana lasts until end of combat.)
Whenever Fire Lord Sozin deals combat damage to a player, you may pay {X}. When you do, put any number of target creature cards with total mana value X or less from that player's graveyard onto the battlefield under your control.

The Rise of Sozin

(As this Saga enters and after your draw step, add a lore counter.)
I — Destroy all creatures.
II — Choose a card name. Search target opponent's graveyard, hand, and library for up to four cards with that name and exile them. Then that player shuffles.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Rise of Sozin // Fire Lord Sozin

Energybending

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

Barrels of Blasting Jelly

{1}: Add one mana of any color. Activate only once each turn.
{5}, {T}, Sacrifice this artifact: It deals 5 damage to target creature.

Azula Always Lies

Choose one or both —
• Target creature gets -1/-1 until end of turn.
• Put a +1/+1 counter on target creature.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Azula, On the Hunt

Firebending 2 (Whenever this creature attacks, add {R}{R}. This mana lasts until end of combat.)
Whenever Azula attacks, you lose 1 life and create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Chakra Meditation

When this enchantment enters, return up to one target instant or sorcery card from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, draw a card. Then discard a card unless there are three or more Lesson cards in your graveyard.

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.)

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.

Lost in Memories

Flash
Enchant creature you control
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost." (You may cast that card from your graveyard for its flashback cost. Then exile it.)

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 Blue Spirit

You may cast the first creature spell you cast each turn as though it had flash.
Whenever a nontoken creature you control enters during combat, draw a card.

Zuko's Exile

Exile target artifact, creature, or enchantment. Its controller creates a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

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.)

Azula, Ruthless Firebender

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Whenever Azula attacks, you may discard a card. Then you get an experience counter for each player who discarded a card this turn.
{2}{B}: Until end of turn, Azula gets +1/+1 for each experience counter you have and gains menace.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

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.)

The Unagi of Kyoshi Island

Flash
Ward—Waterbend {4} (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Whenever an opponent draws their second card each turn, draw two cards.

Frantic Confrontation

Target creature you control gets +X/+0 and gains first strike and trample until end of turn.

Darkwater Catacombs

Command Tower

Callous Inspector

Menace (This creature can't be blocked except by two or more creatures.)
When this creature dies, it deals 1 damage to you. Create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Reliquary Tower

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

Crumbling Necropolis

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

Combustion Man

Whenever Combustion Man attacks, destroy target permanent unless its controller has Combustion Man deal damage to them equal to his power.

Dramatic Reversal

Untap all nonland permanents you control.

Ty Lee, Artful Acrobat

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Ty Lee attacks, you may pay {1}. When you do, target creature can't block this turn.

Wan Shi Tong, Librarian

Flash
Flying, vigilance
When Wan Shi Tong enters, put X +1/+1 counters on him. Then draw half X cards, rounded down.
Whenever an opponent searches their library, put a +1/+1 counter on Wan Shi Tong and draw a card.

Sol Ring

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.

Island

Lightning Strike

Lightning Strike deals 3 damage to any target.

Waterbending Lesson

Draw three cards. Then discard a card unless you waterbend {2}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Dragonskull Summit

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

Fire Nation Turret

At the beginning of combat on your turn, up to one target creature gets +2/+0 and gains firebending 2 until end of turn.
{R}: Put a charge counter on this artifact.
Remove fifty charge counters from this artifact: It deals 50 damage to any target.