Flowstone Flood

Buyback—Pay 3 life, Discard a card at random. (You may pay 3 life and discard a card at random in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target land.

Mountain

Jackal Pup

Whenever Jackal Pup is dealt damage, it deals that much damage to you.

Masticore

At the beginning of your upkeep, sacrifice Masticore unless you discard a card.
{2}: Masticore deals 1 damage to target creature.
{2}: Regenerate Masticore.

Avalanche Riders

Haste
Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Avalanche Riders enters, destroy target land.

Thran Foundry

{1}, {T}, Exile Thran Foundry: Target player shuffles their graveyard into their library.

Scald

Whenever a player taps an Island for mana, Scald deals 1 damage to that player.

Hammer of Bogardan

Hammer of Bogardan deals 3 damage to any target.
{2}{R}{R}{R}: Return Hammer of Bogardan from your graveyard to your hand. Activate only during your upkeep.

Ghitu Encampment

Ghitu Encampment enters tapped.
{T}: Add {R}.
{1}{R}: Ghitu Encampment becomes a 2/1 red Warrior creature with first strike until end of turn. It's still a land. (It deals combat damage before creatures without first strike.)

Fireslinger

{T}: Fireslinger deals 1 damage to any target and 1 damage to you.

Shattering Pulse

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.)
Destroy target artifact.

Wasteland

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

Cursed Scroll

{3}, {T}: Choose a card name, then reveal a card at random from your hand. If that card has the chosen name, Cursed Scroll deals 2 damage to any target.

Arc Lightning

Arc Lightning deals 3 damage divided as you choose among one, two, or three targets.