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.

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.)

Mistrise Village

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn can't be countered.

Cycle of Renewal

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

Agna Qel'a

This land enters tapped unless you control a basic land.
{T}: Add {U}.
{2}{U}, {T}: Draw a card, then discard a card.

Mountain

Starting Town

This land enters tapped unless it's your first, second, or third turn of the game.
{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color.

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.

Island

Ba Sing Se

This land enters tapped unless you control a basic land.
{T}: Add {G}.
{2}{G}, {T}: Earthbend 2. Activate only as a sorcery. (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.)

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.

Stomping Ground

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

Shared Roots

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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.

Breeding Pool

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

Restless Vinestalk

This land enters tapped.
{T}: Add {G} or {U}.
{3}{G}{U}: Until end of turn, this land becomes a 5/5 green and blue Plant creature with trample. It's still a land.
Whenever this land attacks, up to one other target creature has base power and toughness 3/3 until end of turn.

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.

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.

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.

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}.

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.

Willowrush Verge

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

Boomerang Basics

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

Thornspire Verge

{T}: Add {R}.
{T}: Add {G}. Activate only if you control a Mountain or a Forest.

Forest

Riverpyre Verge

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