Fiendish Duo

First strike
If a source would deal damage to an opponent, it deals double that damage to that player instead.

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.

Crater's Claws

Crater's Claws deals X damage to any target.
Ferocious — Crater's Claws deals X plus 2 damage instead if you control a creature with power 4 or greater.

Alloy Myr

Bloodfell Caves

Bloodfell Caves enters tapped.
When Bloodfell Caves enters, you gain 1 life.
{T}: Add {B} or {R}.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Dreadbore

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Murder

Dual Casting

Enchant creature
Enchanted creature has "{R}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy."

Risk Factor

Target opponent may have Risk Factor deal 4 damage to them. If that player doesn't, you draw three cards.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Crawlspace

No more than two creatures can attack you each combat.

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Sizzle

Captivating Crew

{3}{R}: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Akoum Refuge

Akoum Refuge enters tapped.
When Akoum Refuge enters, you gain 1 life.
{T}: Add {B} or {R}.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Mountain

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Terminate

Destroy target creature. It can't be regenerated.

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Blaze

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Scab-Clan Berserker

Haste
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever an opponent casts a noncreature spell, if Scab-Clan Berserker is renowned, Scab-Clan Berserker deals 2 damage to that player.

Lightning Axe

As an additional cost to cast this spell, discard a card or pay {5}.
Lightning Axe deals 5 damage to target creature.

Ravaging Blaze

Ravaging Blaze deals X damage to target creature.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Ravaging Blaze also deals X damage to that creature's controller.

Balefire Dragon

Flying
Whenever Balefire Dragon deals combat damage to a player, it deals that much damage to each creature that player controls.

Temple of Malice

Temple of Malice enters tapped.
When Temple of Malice enters, scry 1.
{T}: Add {B} or {R}.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Stomp

Damage can't be prevented this turn. Stomp deals 2 damage to any target.

Bonecrusher Giant

Whenever Bonecrusher Giant becomes the target of a spell, Bonecrusher Giant deals 2 damage to that spell's controller.

Bonecrusher Giant // Stomp

Wild Slash

Ferocious — If you control a creature with power 4 or greater, damage can't be prevented this turn.
Wild Slash deals 2 damage to any target.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Lightning Skelemental

Trample, haste
Whenever Lightning Skelemental deals combat damage to a player, that player discards two cards.
At the beginning of the end step, sacrifice Lightning Skelemental.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Greed

Extinction Event

Choose odd or even. Exile each creature with mana value of the chosen quality. (Zero is even.)

Shock

Burn from Within

Burn from Within deals X damage to any target. If a creature is dealt damage this way, it loses indestructible until end of turn. If that creature would die this turn, exile it instead.

Devil's Play

Devil's Play deals X damage to any target.
Flashback {X}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters, Rampaging Ferocidon deals 1 damage to that creature's controller.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Thran Dynamo

Obosh, the Preypiercer

Companion — Your starting deck contains only cards with odd mana values and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Rakdos Signet

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Sol Ring

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Fire Servant

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

Breath of Malfegor

Breath of Malfegor deals 5 damage to each opponent.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Cinder Barrens

Cinder Barrens enters tapped.
{T}: Add {B} or {R}.

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 Ball Lightning.

Swamp

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Basalt Monolith

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.

Browbeat

Any player may have Browbeat deal 5 damage to them. If no one does, target player draws three cards.

Yargle, Glutton of Urborg

Command Tower

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Angrath, the Flame-Chained

+1: Each opponent discards a card and loses 2 life.
−3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.
−8: Each opponent loses life equal to the number of cards in their graveyard.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Repeated Reverberation

When you next cast an instant spell, cast a sorcery spell, or activate a loyalty ability this turn, copy that spell or ability twice. You may choose new targets for the copies.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth, Maw of Flames attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.