Downhill Charge

You may sacrifice a Mountain rather than pay this spell's mana cost.
Target creature gets +X/+0 until end of turn, where X is the number of Mountains you control.

Lithophage

At the beginning of your upkeep, sacrifice Lithophage unless you sacrifice a Mountain.

Mountain

Vulshok Sorcerer

Haste
{T}: Vulshok Sorcerer deals 1 damage to any target.

Searing Blaze

Searing Blaze deals 1 damage to target player or planeswalker and 1 damage to target creature that player or that planeswalker's controller controls.
Landfall — If you had a land enter the battlefield under your control this turn, Searing Blaze deals 3 damage to that player or planeswalker and 3 damage to that creature instead.

Spire Barrage

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

Geyser Glider

Landfall — Whenever a land you control enters, Geyser Glider gains flying until end of turn.

Bloodfire Kavu

{R}, Sacrifice Bloodfire Kavu: It deals 2 damage to each creature.

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Stone Giant

{T}: Target creature you control with toughness less than Stone Giant's power gains flying until end of turn. Destroy that creature at the beginning of the next end step.

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.

Aether Membrane

Defender; reach (This creature can block creatures with flying.)
Whenever Aether Membrane blocks a creature, return that creature to its owner's hand at end of combat.

Chartooth Cougar

{R}: Chartooth Cougar gets +1/+0 until end of turn.
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Bloodfire Colossus

{R}, Sacrifice Bloodfire Colossus: It deals 6 damage to each creature and each player.

Pilgrim's Eye

Flying
When Pilgrim's Eye enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Vulshok Morningstar

Equipped creature gets +2/+2.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Seismic Strike

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

Pygmy Pyrosaur

Pygmy Pyrosaur can't block.
{R}: Pygmy Pyrosaur gets +1/+0 until end of turn.

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.

Plated Geopede

First strike
Landfall — Whenever a land you control enters, Plated Geopede gets +2/+2 until end of turn.

Earth Servant

Earth Servant gets +0/+1 for each Mountain you control.

Journeyer's Kite

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Cosi's Ravager

Landfall — Whenever a land you control enters, you may have Cosi's Ravager deal 1 damage to target player or planeswalker.

Volley of Boulders

Volley of Boulders deals 6 damage divided as you choose among any number of targets.
Flashback {R}{R}{R}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Greater Stone Spirit

Greater Stone Spirit can't be blocked by creatures with flying.
{2}{R}: Until end of turn, target creature gets +0/+2 and gains "{R}: This creature gets +1/+0 until end of turn."

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Koth of the Hammer Emblem

Mountains you control have '{T}: This land deals 1 damage to any target.'

Torchling

{R}: Untap Torchling.
{R}: Target creature blocks Torchling this turn if able.
{R}: Change the target of target spell that targets only Torchling.
{1}: Torchling gets +1/-1 until end of turn.
{1}: Torchling gets -1/+1 until end of turn.

Vulshok Battlegear

Equipped creature gets +3/+3.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Vulshok Berserker

Haste (This creature can attack and {T} as soon as it comes under your control.)

Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"