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.

Shared Roots

Search your library for a basic land card, put it 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.

Hermitic Herbalist

{T}: Add one mana of any color.
{T}: Add two mana in any combination of colors. Spend this mana only to cast Lesson spells.

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.)

Island

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.)

Serpent of the Pass

If there are three or more Lesson cards in your graveyard, you may cast this spell as though it had flash.
This spell costs {1} less to cast for each noncreature, nonland card in your graveyard.

Platypus-Bear

Defender
When this creature enters, mill two cards. (Put the top two cards of your library into your graveyard.)
As long as there is a Lesson card in your graveyard, this creature can attack as though it didn't have defender.

Abandon Attachments

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

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.

Walltop Sentries

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

Meditation Pools

This land enters tapped.
{T}: Add {G} or {U}.
{4}, {T}, Sacrifice this land: 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.)