Maybe out

Fear of Burning Alive

When Fear of Burning Alive enters, it deals 4 damage to each opponent.
Delirium — Whenever a source you control deals noncombat damage to an opponent, if there are four or more card types among cards in your graveyard, Fear of Burning Alive deals that amount of damage to target creature that player controls.

Don't Have

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Graven Cairns

{T}: Add {C}.
{B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Tibalt, Cosmic Impostor

As Tibalt enters, you get an emblem with "You may play cards exiled with Tibalt, Cosmic Impostor, and you may spend mana as though it were mana of any color to cast those spells."
+2: Exile the top card of each player's library.
−3: Exile target artifact or creature.
−8: Exile all graveyards. Add {R}{R}{R}.

Have

Valki, God of Lies

When Valki enters, each opponent reveals their hand. For each opponent, exile a creature card they revealed this way until Valki leaves the battlefield.
{X}: Choose a creature card exiled with Valki with mana value X. Valki becomes a copy of that card.

Valki, God of Lies // Tibalt, Cosmic Impostor

Solphim, Mayhem Dominus

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead.
{1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim, Mayhem Dominus. ({R/P} can be paid with either {R} or 2 life.)

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.

No Secret Is Hidden from Me

When you set this scheme in motion, exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost. Then if you control six or more lands, repeat this process once.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, Scytheclaw Raptor deals 4 damage to them.

Witch's Clinic

{T}: Add {C}.
{2}, {T}: Target commander gains lifelink until end of turn.

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters tapped.

Exsanguinate

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

Blood Pact

Target player draws two cards and loses 2 life.

Torture Pit

If a source you control would deal noncombat damage to an opponent, it deals that much damage plus 2 instead.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Spiked Corridor

When you unlock this door, create three 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target."
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Spiked Corridor // Torture Pit

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.

Evolving Wilds

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

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.

Luxury Suite

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

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.

Running Is Useless

When you set this scheme in motion, choose any number of creatures with different mana values. Destroy those creatures.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Fate Unraveler

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

Terramorphic Expanse

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

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.)

Sol Ring

Shivan Gorge

{T}: Add {C}.
{2}{R}, {T}: Shivan Gorge deals 1 damage to each opponent.

I Call for Slaughter

When you set this scheme in motion, create three 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target." They gain haste until end of turn. If a source you control would deal damage this turn, it deals that much damage plus 1 instead.

Florian, Voldaren Scion

First strike
At the beginning of each of your postcombat main phases, look at the top X cards of your library, where X is the total amount of life your opponents lost this turn. Exile one of those cards and put the rest on the bottom of your library in a random order. You may play the exiled card this turn.

Mask of Griselbrand

Equipped creature has flying and lifelink.
Whenever equipped creature dies, you may pay X life, where X is its power. If you do, draw X cards.
Equip {3}

Persistent Constrictor

At the beginning of each opponent's upkeep, they lose 1 life and you put a -1/-1 counter on up to one target creature they control.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with 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.)

Temple of the False God

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

Swamp

Blazemire Verge

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

Mount Doom

{T}, Pay 1 life: Add {B} or {R}.
{1}{B}{R}, {T}: Mount Doom deals 1 damage to each opponent.
{5}{B}{R}, {T}, Sacrifice Mount Doom and a legendary artifact: Choose up to two creatures, then destroy the rest. Activate only as a sorcery.

Blood Artist

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

My Crushing Masterstroke

When you set this scheme in motion, gain control of all nonland permanents your opponents control until end of turn. Untap those permanents. They gain haste until end of turn. Each of them attacks its owner this turn if able.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

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.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Blood Seeker

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

Gleeful Arsonist

Whenever an opponent casts a noncreature spell, Gleeful Arsonist deals damage equal to its power to that player.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Spinerock Knoll enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

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.

Infernal Grasp

Destroy target creature. You lose 2 life.

Rakdos Charm

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

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on Nightshade Harvester.

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.)

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.

Haunted Ridge

Haunted Ridge enters tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

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.

The Lord of Pain

Menace
Your opponents can't gain life.
Whenever a player casts their first spell each turn, choose another target player. The Lord of Pain deals damage equal to that spell's mana value to the chosen player.

Shadowblood Ridge

Bedevil

Destroy target artifact, creature, or planeswalker.

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}.

Dragonskull Summit

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

Star Athlete

Menace
Whenever Star Athlete attacks, choose up to one target nonland permanent. Its controller may sacrifice it. If they don't, Star Athlete deals 5 damage to that player.
Blitz {3}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Feed the Swarm

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

Blasphemous Act

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

Smoldering Marsh

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

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Fear My Authority

(An ongoing scheme remains face up until it's abandoned.)
Creatures you control get +2/+2 and have fear. (They can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, abandon this scheme unless you discard a card or pay 3 life.

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Arcane Signet

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

Valgavoth, Harrower of Souls

Flying
Ward—Pay 2 life.
Whenever an opponent loses life for the first time during each of their turns, put a +1/+1 counter on Valgavoth, Harrower of Souls and draw a card.

Sign in Blood

Tainted Peak

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

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Hidetsugu, Devouring Chaos

{B}, Sacrifice a creature: Scry 2.
{2}{R}, {T}: Exile the top card of your library. You may play that card this turn. When you exile a nonland card this way, Hidetsugu, Devouring Chaos deals damage equal to the exiled card's mana value to any target.

Arena of Glory

Arena of Glory enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert Arena of Glory: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Rakdos Signet

Barbflare Gremlin

First strike, haste
Whenever a player taps a land for mana, if Barbflare Gremlin is tapped, that player adds one mana of any type that land produced. Then that land deals 1 damage to that player.

Blackcleave Cliffs

Blackcleave Cliffs enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Rampaging Ferocidon

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

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

I Will Savor Your Agony

When you set this scheme in motion, choose three. You may choose the same mode more than once.
• Destroy target creature.
• Target player draws a card.
• Target player gains 5 life.

Canyon Slough

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

Mountain

Manabarbs

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

Command Tower

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

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.

Reality Is Mine to Control

(An ongoing scheme remains face up until it's abandoned.)
Whenever you cast a spell, you may abandon this scheme. If you do, copy that spell, and you may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Enchanter's Bane

At the beginning of your end step, target enchantment deals damage equal to its mana value to its controller unless that player sacrifices it.

Rakdos, Lord of Riots

You can't cast Rakdos, Lord of Riots unless an opponent lost life this turn.
Flying, trample
Creature spells you cast cost {1} less to cast for each 1 life your opponents have lost this turn.

Lightning Greaves

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

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Mayhem Devil

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

You Exist Only to Amuse

When you set this scheme in motion, choose one. If you control six or more lands, choose both instead.
• Create three 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target."
• Until your next turn, creatures your opponents control have base power and toughness 1/1 and lose all abilities.

Séance Board

Morbid — At the beginning of each end step, if a creature died this turn, put a soul counter on Séance Board.
{T}: Add X mana of any one color, where X is the number of soul counters on Séance Board. Spend this mana only to cast instant, sorcery, Demon, and Spirit spells.

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.

Leechridden Swamp

({T}: Add {B}.)
Leechridden Swamp enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle Decree of Pain, all creatures get -2/-2 until end of turn.

Jagged Barrens

Jagged Barrens enters tapped.
When Jagged Barrens enters, it deals 1 damage to target opponent.
{T}: Add {B} or {R}.