Mountain

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

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.

Cinderclasm

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Cinderclasm deals 1 damage to each creature. If it was kicked, it deals 2 damage to each creature instead.

Mwonvuli Acid-Moss

Destroy target land. Search your library for a Forest card, put that card onto the battlefield tapped, 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.

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.

Forest

Flame Slash

Flame Slash deals 4 damage to target creature.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Storm's Wrath

Storm's Wrath deals 4 damage to each creature and each planeswalker.

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.