Kor Firewalker

Protection from red
Whenever a player casts a red spell, you may gain 1 life.

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Exquisite Firecraft

Exquisite Firecraft deals 4 damage to any target.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, this spell can't be countered.

Rift Bolt

Rift Bolt deals 3 damage to any target.
Suspend 1—{R} (Rather than cast this card from your hand, you may pay {R} and exile it with a time counter on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Looming Spires

Looming Spires enters tapped.
When Looming Spires enters, target creature gets +1/+1 and gains first strike until end of turn.
{T}: Add {R}.

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Ramunap Ruins

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{2}{R}{R}, {T}, Sacrifice a Desert: Ramunap Ruins deals 2 damage to each opponent.

Mountain

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Goblin Guide

Haste
Whenever Goblin Guide attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Wind-Scarred Crag

Wind-Scarred Crag enters tapped.
When Wind-Scarred Crag enters, you gain 1 life.
{T}: Add {R} or {W}.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Desert of the True

Desert of the True enters tapped.
{T}: Add {W}.
Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.)

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Eidolon of the Great Revel

Whenever a player casts a spell with mana value 3 or less, Eidolon of the Great Revel deals 2 damage to that player.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Smash to Smithereens

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

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.

Lorehold Campus

Lorehold Campus enters tapped.
{T}: Add {R} or {W}.
{4}, {T}: Scry 1.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Skullcrack

Players can't gain life this turn. Damage can't be prevented this turn. Skullcrack deals 3 damage to target player or planeswalker.