The Lion-Turtle

Vigilance, reach
When The Lion-Turtle enters, you gain 3 life.
The Lion-Turtle can't attack or block unless there are three or more Lesson cards in your graveyard.
{T}: Add one mana of any color.

Rugged Highlands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {G}.

Many Partings

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Solstice Revelations

Exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost if the spell's mana value is less than the number of Mountains you control. If you don't cast that card this way, put it into your hand.
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Beacon Bolt

Beacon Bolt deals damage to target creature equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Thriving Grove

This land enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

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.)

Temple of Mystery

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 {G} or {U}.

Command Tower

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

Llanowar Elves

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.)

Gandalf the Grey

Whenever you cast an instant or sorcery spell, choose one that hasn't been chosen —
• You may tap or untap target permanent.
• Gandalf deals 3 damage to each opponent.
• Copy target instant or sorcery spell you control. You may choose new targets for the copy.
• Put Gandalf on top of its owner's library.

Volatile Fjord

({T}: Add {U} or {R}.)
This land enters tapped.

Boomerang Basics

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Firebending Lesson

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Firebending Lesson deals 2 damage to target creature. If this spell was kicked, it deals 5 damage to that creature instead.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Aang's Journey

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card. If this spell was kicked, instead search your library for a basic land card and a Shrine card. Reveal those cards, put them into your hand, then shuffle.
You gain 2 life.

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.

Might of Murasa

Kicker {2}{G} (You may pay an additional {2}{G} as you cast this spell.)
Target creature gets +3/+3 until end of turn. If this spell was kicked, that creature gets +5/+5 until end of turn instead.

Coiling Oracle

When this creature enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Overflowing Basin

Energybending

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

Accumulate Wisdom

Look at the top three cards of your library. Put one of those cards into your hand and the rest on the bottom of your library in any order. Put each of those cards into your hand instead if there are three or more Lesson cards in your graveyard.

Earthbending Lesson

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.)

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Cosmic Hunger

Target creature you control deals damage equal to its power to another target creature, planeswalker, or battle.

Overprotect

Target creature you control gets +3/+3 and gains trample, hexproof, and indestructible until end of turn.

Lush Oasis

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {G} or {U}.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Dragonfly Swarm

Flying, ward {1} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
This creature's power is equal to the number of noncreature, nonland cards in your graveyard.
When this creature dies, if there's a Lesson card in your graveyard, draw a card.

Abandon Attachments

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

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

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.

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.

Sol Ring

Seismic Sense

Look at the top X cards of your library, where X is the number of lands you control. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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.)

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.")

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Fully Grown

Target creature gets +3/+3 until end of turn. Put a trample counter on it.

Mountain

Jeong Jeong, the Deserter

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Exhaust — {3}: Put a +1/+1 counter on Jeong Jeong. When you next cast a Lesson spell this turn, copy it and you may choose new targets for the copy. (Activate each exhaust ability only once.)

Rabid Bite

Target creature you control deals damage equal to its power to target creature you don't control.

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}.

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.

Fire Nation Cadets

This creature has firebending 2 as long as there's a Lesson card in your graveyard. (Whenever this creature attacks, add {R}{R}. This mana lasts until end of combat.)
{2}: This creature gets +1/+0 until end of turn.

Ravaging Blaze

Ravaging Blaze deals X damage to target creature.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Ravaging Blaze also deals X damage to that creature's controller.

Izzet Boilerworks

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

True Ancestry

Return up to one target permanent card from your graveyard to your hand.
Create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Counterspell

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on this creature.

Raging Battle Mouse

The second spell you cast each turn costs {1} less to cast.
Celebration — At the beginning of combat on your turn, if two or more nonland permanents entered the battlefield under your control this turn, target creature you control gets +1/+1 until end of turn.

Zuko, Exiled Prince

Firebending 3 (Whenever this creature attacks, add {R}{R}{R}. This mana lasts until end of combat.)
{3}: Exile the top card of your library. You may play that card this turn.

Cycle of Renewal

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

Match the Odds

Create a 1/1 white Ally creature token. Put a +1/+1 counter on it for each creature your opponents control.

Forest

White Lotus Hideout

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Lesson or Shrine spell.
{1}, {T}: Add one mana of any color.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Price of Freedom

Destroy target artifact or land an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
Draw a card.

Three Tree Rootweaver

Consider

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

Bumi, King of Three Trials

When Bumi enters, choose up to X, where X is the number of Lesson cards in your graveyard —
• Put three +1/+1 counters on Bumi.
• Target player scries 3.
• Earthbend 3. (Target land you control becomes a 0/0 creature with haste that's still a land. Put three +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Frontier Bivouac

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

Sokka's Haiku

Counter target spell.
Draw a card, then mill three cards.
Untap target land.

Gruul Guildgate

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

Lost Days

The owner of target creature or enchantment puts it into their library second from the top or on the bottom. You create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Iroh's Demonstration

Choose one —
• Iroh's Demonstration deals 1 damage to each creature your opponents control.
• Iroh's Demonstration deals 4 damage to target creature.