Mountain

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)
Ulamog's Crusher attacks each combat if able.

Bend or Break

Each player separates all nontoken lands they control into two piles. For each player, one of their piles is chosen by one of their opponents of their choice. Destroy all lands in the chosen piles. Tap all lands in the other piles.

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Smashing Success

Destroy target artifact or land. If an artifact is destroyed this way, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Omnath, Locus of Rage

Landfall — Whenever a land you control enters, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

Impending Disaster

At the beginning of your upkeep, if there are seven or more lands on the battlefield, sacrifice Impending Disaster and destroy all lands.

Desolation Twin

When you cast this spell, create a 10/10 colorless Eldrazi creature token.

Reclaiming Vines

Destroy target artifact, enchantment, or land.

Titania, Protector of Argoth

When Titania, Protector of Argoth 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.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Terravore

Trample
Terravore's power and toughness are each equal to the number of land cards in all graveyards.

Impatience

At the beginning of each player's end step, if that player didn't cast a spell this turn, Impatience deals 2 damage to that player.

Akki Blizzard-Herder

When Akki Blizzard-Herder dies, each player sacrifices a land.

Svella, Ice Shaper

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color."
{6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Gnottvold Slumbermound

Gnottvold Slumbermound enters tapped.
{T}: Add {R}.
{3}{R}{G}{G}, {T}, Sacrifice Gnottvold Slumbermound: Destroy target land. Create a 4/4 green Troll Warrior creature token with trample.

Darksteel Citadel

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Slagwoods Bridge

Slagwoods Bridge enters tapped.
Indestructible
{T}: Add {R} or {G}.

Hurloon Shaman

When Hurloon Shaman dies, each player sacrifices a land.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Pillage

Destroy target artifact or land. It can't be regenerated.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Ravager of the Fells

Trample
Whenever this creature transforms into Ravager of the Fells, it deals 2 damage to target opponent or planeswalker and 2 damage to up to one target creature that player or that planeswalker's controller controls.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ravager of the Fells.

Huntmaster of the Fells

Whenever this creature enters or transforms into Huntmaster of the Fells, create a 2/2 green Wolf creature token and you gain 2 life.
At the beginning of each upkeep, if no spells were cast last turn, transform Huntmaster of the Fells.

Huntmaster of the Fells // Ravager of the Fells

Bust

Boom

Destroy target land you control and target land you don't control.

Boom // Bust

Dryad's Revival

Return target card from your graveyard to your hand.
Flashback {4}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Winter's Grasp

Ignite the Future

Exile the top three cards of your library. Until the end of your next turn, you may play those cards. If this spell was cast from a graveyard, you may play cards this way without paying their mana costs.
Flashback {7}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Tormenting Voice

As an additional cost to cast this spell, discard a card.
Draw two cards.

Kozilek, the Great Distortion

When you cast this spell, if you have fewer than seven cards in hand, draw cards equal to the difference.
Menace
Discard a card with mana value X: Counter target spell with mana value X.

Lay Waste

Destroy target land.
Cycling {2} ({2}, Discard this card: Draw a card.)

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.

Earth Rift

Destroy target land.
Flashback {5}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Violent Impact

Destroy target artifact or land.
Cycling {2} ({2}, Discard this card: Draw a card.)

Creeping Mold

Drownyard Temple

{T}: Add {C}.
{3}: Return Drownyard Temple from your graveyard to the battlefield tapped.

Thoughts of Ruin

Each player sacrifices a land for each card in your hand.

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Tectonic Edge

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

Tectonic Hellion

Haste
Whenever Tectonic Hellion attacks, each player who controls the most lands sacrifices two lands.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Destructive Force

Each player sacrifices five lands. Destructive Force deals 5 damage to each creature.

Molten Rain

Destroy target land. If that land was nonbasic, Molten Rain deals 2 damage to the land's controller.

Tremble

Sunder from Within

Thrill of Possibility

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Seismic Spike

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Ember Swallower

{5}{R}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Ember Swallower becomes monstrous, each player sacrifices three lands.

Artisan of Kozilek

When you cast this spell, you may return target creature card from your graveyard to the battlefield.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Stone Rain

Wreak Havoc

This spell can't be countered.
Destroy target artifact or land.

Wort, the Raidmother

When Wort, the Raidmother enters, create two 1/1 red and green Goblin Warrior creature tokens.
Each red or green instant or sorcery spell you cast has conspire. (As you cast the spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose new targets for the copy.)

Encroaching Wastes

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

Wild Guess

Galvanoth

At the beginning of your upkeep, you may look at the top card of your library. You may cast it without paying its mana cost if it's an instant or sorcery spell.

Wildfire

Each player sacrifices four lands. Wildfire deals 4 damage to each creature.

Forest

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

The Mending of Dominaria

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill two cards, then you may return a creature card from your graveyard to your hand.
III — Return all land cards from your graveyard to the battlefield, then shuffle your graveyard into your library.

Sol Ring

Restock

Return two target cards from your graveyard to your hand. Exile Restock.

Memorial to War

Memorial to War enters tapped.
{T}: Add {R}.
{4}{R}, {T}, Sacrifice Memorial to War: Destroy target land.

Gruul Signet

Centaur Vinecrasher

Trample
Centaur Vinecrasher enters with a number of +1/+1 counters on it equal to the number of land cards in all graveyards.
Whenever a land card is put into a graveyard from anywhere, you may pay {G}{G}. If you do, return Centaur Vinecrasher from your graveyard to your hand.

Once and Future

Return target card from your graveyard to your hand. Put up to one other target card from your graveyard on top of your library. Exile Once and Future.
Adamant — If at least three green mana was spent to cast this spell, instead return those cards to your hand and exile Once and Future.

Waking the Trolls

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target land.
II — Put target land card from a graveyard onto the battlefield under your control.
III — Choose target opponent. If they control fewer lands than you, create a number of 4/4 green Troll Warrior creature tokens with trample equal to the difference.

Terastodon

When Terastodon enters, you may destroy up to three target noncreature permanents. For each permanent put into a graveyard this way, its controller creates a 3/3 green Elephant creature token.

Raze

As an additional cost to cast this spell, sacrifice a land.
Destroy target land.

Icefall

Destroy target artifact or land.
Recover {R}{R} (When a creature is put into your graveyard from the battlefield, you may pay {R}{R}. If you do, return this card from your graveyard to your hand. Otherwise, exile this card.)

Roiling Terrain

Destroy target land, then Roiling Terrain deals damage to that land's controller equal to the number of land cards in that player's graveyard.