Go for the Throat

Ob Nixilis, Captive Kingpin

Flying, trample
Whenever one or more opponents each lose exactly 1 life, put a +1/+1 counter on Ob Nixilis, Captive Kingpin. Exile the top card of your library. Until your next end step, you may play that card.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Mind Stone

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

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.

Hissing Miasma

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

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Needle Drop

Needle Drop deals 1 damage to any target that was dealt damage this turn.
Draw a card.

Shower of Sparks

Shower of Sparks deals 1 damage to target creature and 1 damage to target player or planeswalker.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Blasphemous Act

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

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Lava Dart

Lava Dart deals 1 damage to any target.
Flashback—Sacrifice a Mountain. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Blood Seeker

Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Spark Jolt

Spark Jolt deals 1 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Terminate

Destroy target creature. It can't be regenerated.

Foreboding Ruins

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped.
{T}: Add {B} or {R}.

Expensive Taste

Exile the top two cards of target opponent's library face down. You may look at and play those cards for as long as they remain exiled.

Decadent Dragon

Flying, trample
Whenever Decadent Dragon attacks, create a Treasure token.

Decadent Dragon // Expensive Taste

Spiteful Visions

At the beginning of each player's draw step, that player draws an additional card.
Whenever a player draws a card, Spiteful Visions deals 1 damage to that player.

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Armor of Shadows

Until end of turn, target creature gets +1/+0 and gains indestructible. (Damage and effects that say "destroy" don't destroy it.)

Smoldering Marsh

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

Bedevil

Destroy target artifact, creature, or planeswalker.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Big Score

Nalfeshnee

Flying
Whenever you cast a spell from exile, copy it. You may choose new targets for the copy. If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.)

Wild-Magic Sorcerer

The first spell you cast from exile each turn has cascade. (When you cast your first spell from exile, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

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.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Swamp

Pain Distributor

Menace
Whenever a player casts their first spell each turn, they create a Treasure token.
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, Pain Distributor deals 1 damage to that player.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Flick a Coin

Flick a Coin deals 1 damage to any target. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Draw a card.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Plargg and Nassari

At the beginning of your upkeep, each player exiles cards from the top of their library until they exile a nonland card. An opponent chooses a nonland card exiled this way. You may cast up to two spells from among the other cards exiled this way without paying their mana costs.

Sol Ring

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.

Laelia, the Blade Reforged

Haste
Whenever Laelia, the Blade Reforged attacks, exile the top card of your library. You may play that card this turn.
Whenever one or more cards are put into exile from your library and/or your graveyard, put a +1/+1 counter on Laelia.

Seething Song

Defiler of Instinct

First strike
As an additional cost to cast red permanent spells, you may pay 2 life. Those spells cost {R} less to cast if you paid life this way. This effect reduces only the amount of red mana you pay.
Whenever you cast a red permanent spell, Defiler of Instinct deals 1 damage to any target.

Soot Imp

Flying
Whenever a player casts a nonblack spell, that player loses 1 life.

Dark Ritual

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Rakdos Signet

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Mountain

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Solemn Simulacrum

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

Arcane Signet

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

Rampaging Ferocidon

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

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Infernal Grasp

Destroy target creature. You lose 2 life.

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.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.