Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Ioreth of the Healing House

{T}: Untap another target permanent.
{T}: Untap two other target legendary creatures.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Clever Conjurer

Mage Hand — {T}: Untap target permanent not named Clever Conjurer. Activate only as a sorcery.

Deathrite Shaman

{T}: Exile target land card from a graveyard. Add one mana of any color.
{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.
{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Kiora's Follower

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Assassin's Trophy

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

Garth One-Eye

{T}: Choose a card name that hasn't been chosen from among Disenchant, Braingeyser, Terror, Shivan Dragon, Regrowth, and Black Lotus. Create a copy of the card with the chosen name. You may cast the copy. (You still pay its costs.)

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Llanowar Elves

Faeburrow Elder

Vigilance
Faeburrow Elder gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Negate

Vizier of Tumbling Sands

{T}: Untap another target permanent.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Vizier of Tumbling Sands, untap target permanent.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Dramatic Reversal

Untap all nonland permanents you control.

Counterspell

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Birds of Paradise

Kelpie Guide

{T}: Untap another target permanent you control.
{T}: Tap target permanent. Activate only if you control eight or more lands.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.