Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Anger of the Gods

Anger of the Gods deals 3 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Spellshock

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

Mana Geyser

Add {R} for each tapped land your opponents control.

Magus of the Moon

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.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Smoldering Marsh

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

Unlicensed Disintegration

Destroy target creature. If you control an artifact, Unlicensed Disintegration deals 3 damage to that creature's controller.

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.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Blood Crypt

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

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature. If a player does, tap Desecration Demon and put a +1/+1 counter on it.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

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.

Cursed Totem

Activated abilities of creatures can't be activated.

Sol Ring

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

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.

Mountain

Ribbons

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each opponent loses X life.

Cut // Ribbons

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Fellwar Stone

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

Talisman of Indulgence

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

Furnace of Rath

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

Blood Moon

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control, then sacrifices a third of the lands they control. Round up each time.

Master of Cruelties

First strike, deathtouch
Master of Cruelties can only attack alone.
Whenever Master of Cruelties attacks a player and isn't blocked, that player's life total becomes 1. Master of Cruelties assigns no combat damage this combat.

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.

Bedevil

Destroy target artifact, creature, or planeswalker.

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

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.)

Terminate

Destroy target creature. It can't be regenerated.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Azra Oddsmaker

At the beginning of combat on your turn, you may discard a card. If you do, choose a creature. Whenever that creature deals combat damage to a player this turn, you draw two cards.

Subversion

At the beginning of your upkeep, each opponent loses 1 life. You gain life equal to the life lost this way.

Phyrexian Arena

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Tormenting Voice

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

Magus of the Wheel

{1}{R}, {T}, Sacrifice Magus of the Wheel: Each player discards their hand, then draws seven cards.

Exotic Orchard

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Command Tower

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

Thorn of the Black Rose

Deathtouch
When Thorn of the Black Rose enters, you become the monarch.

Fanatic of Mogis

When Fanatic of Mogis enters, it deals damage to each opponent equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Sulfuric Vortex

At the beginning of each player's upkeep, Sulfuric Vortex deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Dragonskull Summit

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

Red Elemental Blast

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

Manabarbs

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

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Skull Rend

Skull Rend deals 2 damage to each opponent. Those players each discard two cards at random.

Swamp

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Anax, Hardened in the Forge

Anax's power is equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
Whenever Anax or another nontoken creature you control dies, create a 1/1 red Satyr creature token with "This creature can't block." If the creature had power 4 or greater, create two of those tokens instead.

Rakdos Signet

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Mayhem Devil

Whenever a player sacrifices a permanent, Mayhem Devil deals 1 damage to any target.

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.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Sign in Blood

Target player draws two cards and loses 2 life.

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Evolving Wilds

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

Arcane Signet

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Rix Maadi, Dungeon Palace

{T}: Add {C}.
{1}{B}{R}, {T}: Each player discards a card. Activate only as a sorcery.

Terramorphic Expanse

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

Thrill of Possibility

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.

Zo-Zu the Punisher

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

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Tangle Wire

Fading 4 (This artifact enters with four fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
At the beginning of each player's upkeep, that player taps an untapped artifact, creature, or land they control for each fade counter on Tangle Wire.