Soulsurge Elemental

First strike
Soulsurge Elemental's power is equal to the number of creatures you control.

Scourge of Geier Reach

Scourge of Geier Reach gets +1/+1 for each creature your opponents control.

Magmatic Force

At the beginning of each upkeep, Magmatic Force deals 3 damage to any target.

Hellspark Elemental

Trample, haste
At the beginning of the end step, sacrifice Hellspark Elemental.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Fire Servant

If a red instant or sorcery spell you control would deal damage, it deals double that damage instead.

Malignus

Malignus's power and toughness are each equal to half the highest life total among your opponents, rounded up.
Damage that would be dealt by Malignus can't be prevented.

Mountain

Hellion Crucible

{T}: Add {C}.
{1}{R}, {T}: Put a pressure counter on Hellion Crucible.
{1}{R}, {T}, Remove two pressure counters from Hellion Crucible and sacrifice it: Create a 4/4 red Hellion creature token with haste. (It can attack and {T} as soon as it comes under your control.)

Volcanic Strength

Enchant creature
Enchanted creature gets +2/+2 and has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)

Surreal Memoir

Return an instant card at random from your graveyard to your hand.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Skullcrack

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

Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

Rage Reflection

Creatures you control have double strike.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Hell's Thunder

Flying, haste
At the beginning of the end step, sacrifice Hell's Thunder.
Unearth {4}{R} ({4}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Pyrite Spellbomb

{R}, Sacrifice Pyrite Spellbomb: It deals 2 damage to any target.
{1}, Sacrifice Pyrite Spellbomb: Draw a card.

Claws of Valakut

Enchant creature
Enchanted creature gets +1/+0 for each Mountain you control and has first strike.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Refraction Elemental

Ward—Pay 2 life.
Whenever you cast a spell, Refraction Elemental deals 2 damage to each opponent.

Invasion of Karsus

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Karsus enters, it deals 3 damage to each creature and each planeswalker.

Invasion of Karsus // Refraction Elemental

Smoldering Spires

Smoldering Spires enters tapped.
When Smoldering Spires enters, target creature can't block this turn.
{T}: Add {R}.

Skizzik

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Trample, haste
At the beginning of the end step, if Skizzik wasn't kicked, sacrifice it.

Chandra, Dressed to Kill

+1: Add {R}. Chandra, Dressed to Kill deals 1 damage to up to one target player or planeswalker.
+1: Exile the top card of your library. If it's red, you may cast it this turn.
−7: Exile the top five cards of your library. You may cast red spells from among them this turn. You get an emblem with "Whenever you cast a red spell, this emblem deals X damage to any target, where X is the amount of mana spent to cast that spell."

Double Vision

Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copy.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Rockslide Elemental

First strike
Whenever another creature dies, you may put a +1/+1 counter on Rockslide Elemental.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, Chandra's Spitfire gets +3/+0 until end of turn.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Spark Elemental

Trample, haste (This creature can deal excess combat damage to the player or planeswalker it's attacking. This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Spark Elemental.

Pyretic Ritual

Magma Pummeler

Magma Pummeler enters with X +1/+1 counters on it.
If damage would be dealt to Magma Pummeler while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it. When one or more counters are removed from Magma Pummeler this way, it deals that much damage to any target.

Rakka Mar

Haste
{R}, {T}: Create a 3/1 red Elemental creature token with haste.

Soulbright Flamekin

{2}: Target creature gains trample until end of turn. If this is the third time this ability has resolved this turn, you may add {R}{R}{R}{R}{R}{R}{R}{R}.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Coal Stoker

When Coal Stoker enters, if you cast it from your hand, add {R}{R}{R}.

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Lightning Serpent

Trample, haste
Lightning Serpent enters with X +1/+0 counters on it.
At the beginning of the end step, sacrifice Lightning Serpent.

Flame Slash

Flame Slash deals 4 damage to target creature.

Tectonic Giant

Whenever Tectonic Giant attacks or becomes the target of a spell an opponent controls, choose one —
• Tectonic Giant deals 3 damage to each opponent.
• Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

Searing Spear

Searing Spear deals 3 damage to any target.

Kiln Fiend

Whenever you cast an instant or sorcery spell, Kiln Fiend gets +3/+0 until end of turn.

Ashling, Flame Dancer

You don't lose unspent red mana as steps and phases end.
Magecraft — Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Ashling, Flame Dancer deals 2 damage to each opponent and each creature they control. If it's the third time, add {R}{R}{R}{R}.

Teetering Peaks

Teetering Peaks enters tapped.
When Teetering Peaks enters, target creature gets +2/+0 until end of turn.
{T}: Add {R}.