Rubblehulk

Rubblehulk's power and toughness are each equal to the number of lands you control.
Bloodrush — {1}{R}{G}, Discard this card: Target attacking creature gets +X/+X until end of turn, where X is the number of lands you control.

Wasteland

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target nonbasic land.

Blood Moon

Dwarven Miner

{2}{R}, {T}: Destroy target nonbasic land.

Ruin

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Ruin deals damage to target creature equal to the number of lands you control.

Road

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

Road // Ruin

Titania, Protector of Argoth

When Titania enters, return target land card from your graveyard to the battlefield.
Whenever a land you control is put into a graveyard from the battlefield, create a 5/3 green Elemental creature token.

Dualcaster Mage

Flash
When this creature enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Encroaching Wastes

{T}: Add {C}.
{4}, {T}, Sacrifice this land: Destroy target nonbasic land.

Phylath, World Sculptor

When Phylath enters, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land you control enters, put four +1/+1 counters on target Plant you control.

Spectrum Sentinel

Protection from multicolored (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything multicolored.)
Whenever a nonbasic land an opponent controls enters, you gain 1 life.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Treacherous Terrain

Treacherous Terrain deals damage to each opponent equal to the number of lands that player controls.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Volcanic Offering

Destroy target nonbasic land you don't control and target nonbasic land of an opponent's choice you don't control.
Volcanic Offering deals 7 damage to target creature you don't control and 7 damage to target creature of an opponent's choice you don't control.

Increasing Vengeance

Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reiterate

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Copy target instant or sorcery spell. You may choose new targets for the copy.

Primal Order

At the beginning of each player's upkeep, this enchantment deals damage to that player equal to the number of nonbasic lands they control.

Magus of the Moon

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Three Visits

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

Ruination

Dust Bowl

{T}: Add {C}.
{3}, {T}, Sacrifice a land: Destroy target nonbasic land.

Wrenn and Seven

+1: Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.
0: Put any number of land cards from your hand onto the battlefield tapped.
−3: Create a green Treefolk creature token with reach and "This token's power and toughness are each equal to the number of lands you control."
−8: Return all permanent cards from your graveyard to your hand. You get an emblem with "You have no maximum hand size."

Strip Mine

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land.

Fury Storm

When you cast this spell, copy it for each time you've cast your commander from the command zone this game. You may choose new targets for the copies.
Copy target instant or sorcery spell. You may choose new targets for the copy.

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Wave of Vitriol

Each player sacrifices all artifacts, enchantments, and nonbasic lands they control. For each land sacrificed this way, its controller may search their library for a basic land card and put it onto the battlefield tapped. Then each player who searched their library this way shuffles.

Revolutionist

When this creature enters, return target instant or sorcery card from your graveyard to your hand.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Wilderness Elemental

Trample
Wilderness Elemental's power is equal to the number of nonbasic lands your opponents control.

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Detritivore

Detritivore's power and toughness are each equal to the number of nonbasic land cards in your opponents' graveyards.
Suspend X—{X}{3}{R}. X can't be 0. (Rather than cast this card from your hand, you may pay {X}{3}{R} and exile it with X time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever a time counter is removed from this card while it's exiled, destroy target nonbasic land.

Wrenn and Realmbreaker

Lands you control have "{T}: Add one mana of any color."
+1: Up to one target land you control becomes a 3/3 Elemental creature with vigilance, hexproof, and haste until your next turn. It's still a land.
−2: Mill three cards. You may put a permanent card from among the milled cards into your hand.
−7: You get an emblem with "You may play lands and cast permanent spells from your graveyard."

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Thalia, Heretic Cathar

First strike
Creatures and nonbasic lands your opponents control enter tapped.

Wrenn and Six

+1: Return up to one target land card from your graveyard to your hand.
−1: Wrenn and Six deals 1 damage to any target.
−7: You get an emblem with "Instant and sorcery cards in your graveyard have retrace." (You may cast instant and sorcery cards from your graveyard by discarding a land card in addition to paying their other costs.)

From the Ashes

Destroy all nonbasic lands. For each land destroyed this way, its controller may search their library for a basic land card and put it onto the battlefield. Then each player who searched their library this way shuffles.

Terra Ravager

Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of lands defending player controls.

Wild Ricochet

You may choose new targets for target instant or sorcery spell. Then copy that spell. You may choose new targets for the copy.

Rampant Growth

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

Dwarven Blastminer

{2}{R}, {T}: Destroy target nonbasic land.
Morph {R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Skyshroud War Beast

Trample
As this creature enters, choose an opponent.
Skyshroud War Beast's power and toughness are each equal to the number of nonbasic lands the chosen player controls.

Kodama's Reach

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.

Mercadia's Downfall

Each attacking creature gets +1/+0 until end of turn for each nonbasic land defending player controls.

Tempt with Discovery

Tempting offer — Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

Shivan Harvest

{1}{R}, Sacrifice a creature: Destroy target nonbasic land.

Nature's Lore

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

Cultivate

Tectonic Edge

{T}: Add {C}.
{1}, {T}, Sacrifice this land: Destroy target nonbasic land. Activate only if an opponent controls four or more lands.

Myriad Construct

Kicker {3}
If this creature was kicked, it enters with a +1/+1 counter on it for each nonbasic land your opponents control.
When this creature becomes the target of a spell, sacrifice it and create a number of 1/1 colorless Construct artifact creature tokens equal to its power.

Elturel Survivors

Trample, myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
As long as this creature is attacking, it gets +X/+0, where X is the number of lands defending player controls.