Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Spellshock

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

Savai Triome

({T}: Add {R}, {W}, or {B}.)
Savai Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

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.

Daxos the Returned

Whenever you cast an enchantment spell, you get an experience counter.
{1}{W}{B}: Create a white and black Spirit enchantment creature token. It has "This creature's power and toughness are each equal to the number of experience counters you have."

Snow-Covered Mountain

Everlasting Torment

Players can't gain life.
Damage can't be prevented.
All damage is dealt as though its source had wither. (A source with wither deals damage to creatures in the form of -1/-1 counters.)

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Command Tower

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

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Charging Tuskodon

Trample
If Charging Tuskodon would deal combat damage to a player, it deals double that damage to that player instead.

Soul-Scar Mage

Prowess
If a source you control would deal noncombat damage to a creature an opponent controls, put that many -1/-1 counters on that creature instead.

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Sunforger

Equipped creature gets +4/+0.
{R}{W}, Unattach Sunforger: Search your library for a red or white instant card with mana value 4 or less and cast that card without paying its mana cost. Then shuffle.
Equip {3}

Blasphemous Act

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

Blood Cultist

{T}: Blood Cultist deals 1 damage to target creature.
Whenever a creature dealt damage by Blood Cultist this turn dies, put a +1/+1 counter on Blood Cultist.

Scoured Barrens

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {B}.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, 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.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Grim Lavamancer

{R}, {T}, Exile two cards from your graveyard: Grim Lavamancer deals 2 damage to any target.

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Terramorphic Expanse

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

Snow-Covered Swamp

Cunning Sparkmage

Haste
{T}: Cunning Sparkmage deals 1 damage to any target.

Fire Servant

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

Kelsien, the Plague

Vigilance, haste
Kelsien, the Plague gets +1/+1 for each experience counter you have.
{T}: Kelsien deals 1 damage to target creature you don't control. When that creature dies this turn, you get an experience counter.

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.

Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Blazing Salvo

Blazing Salvo deals 3 damage to target creature unless that creature's controller has Blazing Salvo deal 5 damage to them.

Death Pits of Rath

Whenever a creature is dealt damage, destroy it. It can't be regenerated.

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Giver of Runes

{T}: Another target creature you control gains protection from colorless or from the color of your choice until end of turn.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Gratuitous Violence

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

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Verge Rangers

First strike
You may look at the top card of your library any time.
As long as an opponent controls more lands than you, you may play lands from the top of your library. (You can play a land this way only if you have an available land play remaining.)

Kolaghan's Command

Choose two —
• Return target creature card from your graveyard to your hand.
• Target player discards a card.
• Destroy target artifact.
• Kolaghan's Command deals 2 damage to any target.

Blightning

Blightning deals 3 damage to target player or planeswalker. That player or that planeswalker's controller discards two cards.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Browbeat

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

Weight of Spires

Weight of Spires deals damage to target creature equal to the number of nonbasic lands that creature's controller controls.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Weathered Wayfarer

{W}, {T}: Search your library for a land card, reveal it, put it into your hand, then shuffle. Activate only if an opponent controls more lands than you.

Kederekt Parasite

Whenever an opponent draws a card, if you control a red permanent, you may have Kederekt Parasite deal 1 damage to that player.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Stuffy Doll

Indestructible
As Stuffy Doll enters, choose a player.
Whenever Stuffy Doll is dealt damage, it deals that much damage to the chosen player.
{T}: Stuffy Doll deals 1 damage to itself.

Tresserhorn Sinks

Tresserhorn Sinks enters tapped.
{T}: Add {B} or {R}.

Goblin Sharpshooter

Goblin Sharpshooter doesn't untap during your untap step.
Whenever a creature dies, untap Goblin Sharpshooter.
{T}: Goblin Sharpshooter deals 1 damage to any target.

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.

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.

Ankle Shanker

Haste
Whenever Ankle Shanker attacks, creatures you control gain first strike and deathtouch until end of turn.

Bitter Feud

As Bitter Feud enters, choose two players.
If a source controlled by one of the chosen players would deal damage to the other chosen player or a permanent that player controls, that source deals double that damage to that player or permanent instead.

Rite of the Raging Storm

Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this creature."

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Volcanic Offering

Destroy target nonbasic land you don't control and target nonbasic land of an opponent's choice you don't control.
Volcanic Offering deals 7 damage to target creature you don't control and 7 damage to target creature of an opponent's choice you don't control.

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.)

Burnished Hart

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

Pyroblast

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

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Red Elemental Blast

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

Snow-Covered Plains

Akoum Refuge

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

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.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Vithian Stinger

{T}: Vithian Stinger deals 1 damage to any target.
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.)

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Valakut Exploration

Landfall — Whenever a land you control enters, exile the top card of your library. You may play that card for as long as it remains exiled.
At the beginning of your end step, if there are cards exiled with Valakut Exploration, put them into their owner's graveyard, then Valakut Exploration deals that much damage to each opponent.

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Breaking Point

Any player may have Breaking Point deal 6 damage to them. If no one does, destroy all creatures. Creatures destroyed this way can't be regenerated.

Syr Carah, the Bold

Whenever Syr Carah, the Bold or an instant or sorcery spell you control deals damage to a player, exile the top card of your library. You may play that card this turn.
{T}: Syr Carah deals 1 damage to any target.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Evolving Wilds

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

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Chandra, Roaring Flame

+1: Chandra, Roaring Flame deals 2 damage to target player or planeswalker.
−2: Chandra, Roaring Flame deals 2 damage to target creature.
−7: Chandra, Roaring Flame deals 6 damage to each opponent. Each player dealt damage this way gets an emblem with "At the beginning of your upkeep, this emblem deals 3 damage to you."

Chandra, Fire of Kaladesh

Whenever you cast a red spell, untap Chandra, Fire of Kaladesh.
{T}: Chandra, Fire of Kaladesh deals 1 damage to target player or planeswalker. If Chandra has dealt 3 or more damage this turn, exile her, then return her to the battlefield transformed under her owner's control.

Chandra, Fire of Kaladesh // Chandra, Roaring Flame

Quest for Pure Flame

Whenever a source you control deals damage to an opponent, you may put a quest counter on Quest for Pure Flame.
Remove four quest counters from Quest for Pure Flame and sacrifice it: If any source you control would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

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.

Anthem of Rakdos

Whenever a creature you control attacks, it gets +2/+0 until end of turn and Anthem of Rakdos deals 1 damage to you.
Hellbent — As long as you have no cards in hand, if a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.