Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Barrel Down Sokenzan

Sweep — Return any number of Mountains you control to their owner's hand. Barrel Down Sokenzan deals damage to target creature equal to twice the number of Mountains returned this way.

Blood Moon

Forest

Stonefury

Stonefury deals damage to target creature equal to the number of lands you control.

Storm Cauldron

Each player may play an additional land during each of their turns.
Whenever a land is tapped for mana, return it to its owner's hand.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Survive

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each player shuffles their graveyard into their library.

Struggle

Struggle deals damage to target creature equal to the number of lands you control.

Struggle // Survive

Kaboom!

Choose any number of target players or planeswalkers. For each of them, reveal cards from the top of your library until you reveal a nonland card, Kaboom! deals damage equal to that card's mana value to that player or planeswalker, then you put the revealed cards on the bottom of your library in any order.

Scapeshift

Sacrifice any number of lands. Search your library for up to that many land cards, put them onto the battlefield tapped, then shuffle.

Mountain

Radha, Heart of Keld

During your turn, Radha, Heart of Keld has first strike.
You may look at the top card of your library any time, and you may play lands from the top of your library.
{4}{R}{G}: Radha gets +X/+X until end of turn, where X is the number of lands you control.

Vesuva

You may have Vesuva enter tapped as a copy of any land on the battlefield.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Reverberate

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

Lightning Storm

Lightning Storm deals X damage to any target, where X is 3 plus the number of charge counters on Lightning Storm.
Discard a land card: Put two charge counters on Lightning Storm. You may choose a new target for it. Any player may activate this ability but only if Lightning Storm is on the stack.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Reroute

Change the target of target activated ability with a single target. (Mana abilities can't be targeted.)
Draw a card.

Ben-Ben, Akki Hermit

{T}: Ben-Ben, Akki Hermit deals damage to target attacking creature equal to the number of untapped Mountains you control.

By Force

Nahiri's Lithoforming

Sacrifice X lands. For each land sacrificed this way, draw a card. You may play X additional lands this turn. Lands you control enter tapped this turn.

Eternal Flame

Eternal Flame deals X damage to target opponent or planeswalker and half X damage, rounded up, to you, where X is the number of Mountains you control.

Spire Barrage

Spire Barrage deals damage to any target equal to the number of Mountains you control.

Magus of the Moon

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Dokai, Weaver of Life

{4}{G}{G}, {T}: Create an X/X green Elemental creature token, where X is the number of lands you control.

Budoka Gardener

{T}: You may put a land card from your hand onto the battlefield. If you control ten or more lands, flip Budoka Gardener.

Budoka Gardener // Dokai, Weaver of Life

Rockslide Ambush

Rockslide Ambush deals damage to target creature equal to the number of Mountains you control.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Rumbling Rockslide

Rumbling Rockslide deals damage to target creature equal to the number of lands you control.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Ghirapur Orrery

Each player may play an additional land on each of their turns.
At the beginning of each player's upkeep, if that player has no cards in hand, that player draws three cards.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Borborygmos Enraged

Trample
Whenever Borborygmos Enraged deals combat damage to a player, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.
Discard a land card: Borborygmos Enraged deals 3 damage to any target.

Fire-Lit Thicket

{T}: Add {C}.
{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

Ground Assault

Ground Assault deals damage to target creature equal to the number of lands you control.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Tribal Flames

Domain — Tribal Flames deals X damage to any target, where X is the number of basic land types among lands you control.

Spawn of Thraxes

Flying
When Spawn of Thraxes enters, it deals damage to any target equal to the number of Mountains you control.

Landslide

Sacrifice any number of Mountains. Landslide deals that much damage to target player or planeswalker.

Earth Tremor

Earth Tremor deals damage to target creature or planeswalker equal to the number of lands you control.

Zendikar Incarnate

Zendikar Incarnate's power is equal to the number of lands you control.

Blasphemous Act

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

Exploding Borders

Domain — Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Exploding Borders deals X damage to target player or planeswalker, where X is the number of basic land types among lands you control.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Thawing Glaciers

Thawing Glaciers enters tapped.
{1}, {T}: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return Thawing Glaciers to its owner's hand at the beginning of the next cleanup step.

Seismic Strike

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Spitting Earth

Spitting Earth deals damage to target creature equal to the number of Mountains you control.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Jaws of Stone

Jaws of Stone deals X damage divided as you choose among any number of targets, where X is the number of Mountains you control as you cast this spell.

Kamahl's Druidic Vow

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Look at the top X cards of your library. You may put any number of land and/or legendary permanent cards with mana value X or less from among them onto the battlefield. Put the rest into your graveyard.

Okina, Temple to the Grandfathers

{T}: Add {G}.
{G}, {T}: Target legendary creature gets +1/+1 until end of turn.

Tree of Tales

Scouting Trek

Search your library for any number of basic land cards, reveal those cards, then shuffle and put them on top.

Grove of the Burnwillows

{T}: Add {C}.
{T}: Add {R} or {G}. Each opponent gains 1 life.

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.