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.

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.")

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.)

Rough Rhino Cavalry

Firebending 2 (Whenever this creature attacks, add {R}{R}. This mana lasts until end of combat.)
Exhaust — {8}: Put two +1/+1 counters on this creature. It gains trample until end of turn. (Activate each exhaust ability only once.)

Fire Sages

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
{1}{R}{R}: Put a +1/+1 counter on this creature.

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.)

Ran and Shaw

Flying, firebending 2
When Ran and Shaw enter, if you cast them and there are three or more Dragon and/or Lesson cards in your graveyard, create a token that's a copy of Ran and Shaw, except it's not legendary.
{3}{R}: Dragons you control get +2/+0 until end of turn.

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.

Forest

Ostrich-Horse

When this creature enters, mill three cards. You may put a land card from among them into your hand. If you don't, put a +1/+1 counter on this creature. (To mill three cards, put the top three cards of your library into your graveyard.)

Earth Village Ruffians

When this creature dies, 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.)

Boar-q-pine

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

Wandering Musicians

Whenever this creature attacks, creatures you control get +1/+0 until end of turn.

Foggy Swamp Vinebender

This creature can't be blocked by creatures with power 2 or less.
Waterbend {5}: Put a +1/+1 counter on this creature. Activate only during your turn. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

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.")

Raucous Audience

{T}: Add {G}. If you control a creature with power 4 or greater, add {G}{G} instead.

Earth Rumble Wrestlers

Reach
This creature gets +1/+0 and has trample as long as you control a land creature or a land entered the battlefield under your control this turn.

Earth Kingdom General

When this creature enters, 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.)
Whenever you put one or more +1/+1 counters on a creature, you may gain that much life. Do this only once each turn.

Mountain

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.

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.

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.)

Allies at Last

Affinity for Allies (This spell costs {1} less to cast for each Ally you control.)
Up to two target creatures you control each deal damage equal to their power to target creature an opponent controls.

Treetop Freedom Fighters

Haste
When this creature enters, create a 1/1 white Ally creature token.

Professor Zei, Anthropologist

{T}, Discard a card: Draw a card.
{1}, {T}, Sacrifice Professor Zei: Return target instant or sorcery card from your graveyard to your hand. Activate only during your turn.

Toph, Hardheaded Teacher

When Toph enters, you may discard a card. If you do, return target instant or sorcery card from your graveyard to your hand.
Whenever you cast a spell, earthbend 1. If that spell is a Lesson, put an additional +1/+1 counter on that land. (Target land you control becomes a 0/0 creature with haste that's still a land. Put a +1/+1 counter on it. When it dies or is exiled, return it to the battlefield tapped.)

Walltop Sentries

Reach, deathtouch
When this creature dies, if there's a Lesson card in your graveyard, you gain 2 life.