Quest for the Nihil Stone

Whenever an opponent discards a card, you may put a quest counter on Quest for the Nihil Stone.
At the beginning of each opponent's upkeep, if that player has no cards in hand and Quest for the Nihil Stone has two or more quest counters on it, you may have that player lose 5 life.

Bone Miser

Whenever you discard a creature card, create a 2/2 black Zombie creature token.
Whenever you discard a land card, add {B}{B}.
Whenever you discard a noncreature, nonland card, draw a card.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Grave Consequences

Each player may exile any number of cards from their graveyard. Then each player loses 1 life for each card in their graveyard.
Draw a card.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Halls of Mist

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Creatures that attacked during their controller's last turn can't attack.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

Thoughtrender Lamia

Constellation — Whenever Thoughtrender Lamia or another enchantment enters the battlefield under your control, each opponent discards a card.

Consume Spirit

Spend only black mana on X.
Consume Spirit deals X damage to any target and you gain X life.

Subversion

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

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Word of Command

Look at target opponent's hand and choose a card from it. You control that player until Word of Command finishes resolving. The player plays that card if able. While doing so, the player can activate mana abilities only if they're from lands that player controls and only if mana they produce is spent to activate other mana abilities of lands the player controls and/or to play that card. If the chosen card is cast as a spell, you control the player while that spell is resolving.

Seizan, Perverter of Truth

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Marchesa's Decree

When Marchesa's Decree enters the battlefield, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.

Sword-Point Diplomacy

Reveal the top three cards of your library. For each of those cards, put that card into your hand unless any opponent pays 3 life. Then exile the rest.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents.

Mindcrank

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

Lich's Mastery

Hexproof
You can't lose the game.
Whenever you gain life, draw that many cards.
Whenever you lose life, for each 1 life you lost, exile a permanent you control or a card from your hand or graveyard.
When Lich's Mastery leaves the battlefield, you lose the game.

Storm Cauldron

Each player may play an additional land during each of their turns.
Whenever a land is tapped for mana, return it to its owner's hand.

Model of Unity

Whenever players finish voting, you and each opponent who voted for a choice you voted for may scry 2.
{T}: Add one mana of any color.

Ivory Crane Netsuke

At the beginning of your upkeep, if you have seven or more cards in hand, you gain 4 life.

Death Watch

Enchant creature
When enchanted creature dies, its controller loses life equal to its power and you gain life equal to its toughness.

Tyrant's Choice

Will of the council — Starting with you, each player votes for death or torture. If death gets more votes, each opponent sacrifices a creature. If torture gets more votes or the vote is tied, each opponent loses 4 life.

Epicure of Blood

Whenever you gain life, each opponent loses 1 life.

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.

Chancellor of the Dross

You may reveal this card from your opening hand. If you do, at the beginning of the first upkeep, each opponent loses 3 life, then you gain life equal to the life lost this way.
Flying, lifelink

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Dredge the Mire

Each opponent chooses a creature card in their graveyard. Put those cards onto the battlefield under your control.

Fraying Line

When Fraying Line enters the battlefield, put a rope counter on target creature you control.
At the beginning of each player's upkeep, that player may pay {2}. If they do, they put a rope counter on a creature they control. Otherwise, exile Fraying Line and each creature without a rope counter on it, then remove all rope counters from all creatures.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Herald of Anguish

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Flying
At the beginning of your end step, each opponent discards a card.
{1}{B}, Sacrifice an artifact: Target creature gets -2/-2 until end of turn.

No Mercy

Whenever a creature deals damage to you, destroy it.

False Cure

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life they gained.

Phantasmagorian

When you cast this spell, any player may discard three cards. If a player does, counter Phantasmagorian.
Discard three cards: Return Phantasmagorian from your graveyard to your hand.

Spellbook

Decimator Web

{4}, {T}: Target opponent loses 2 life, gets a poison counter, then mills six cards.

Cursed Rack

As Cursed Rack enters the battlefield, choose an opponent.
The chosen player's maximum hand size is four.

Well of Knowledge

{2}: Draw a card. Any player may activate this ability but only during their draw step.

Explore the Vastlands

Each player looks at the top five cards of their library and may reveal a land card and/or an instant or sorcery card from among them. Each player puts the cards they revealed this way into their hand and the rest on the bottom of their library in a random order. Each player gains 3 life.

Wandering Archaic

Whenever an opponent casts an instant or sorcery spell, they may pay {2}. If they don't, you may copy that spell. You may choose new targets for the copy.

Wandering Archaic // Explore the Vastlands

Exquisite Blood

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

Bottled Cloister

At the beginning of each opponent's upkeep, exile all cards from your hand face down.
At the beginning of your upkeep, return all cards you own exiled with Bottled Cloister to your hand, then draw a card.

Shrieking Affliction

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Marauding Blight-Priest

Rhystic Tutor

Unless any player pays {2}, search your library for a card, put that card into your hand, then shuffle.

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice Fountain of Renewal: Draw a card.

Ivory Tower

At the beginning of your upkeep, you gain X life, where X is the number of cards in your hand minus 4.

Spoils of Blood

Create an X/X black Horror creature token, where X is the number of creatures that died this turn.

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Tempting Contract

At the beginning of your upkeep, each opponent may create a Treasure token. For each opponent who does, you create a Treasure token.

Underworld Dreams

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

Echo Chamber

{4}, {T}: An opponent chooses target creature they control. Create a token that's a copy of that creature. That token gains haste until end of turn. Exile the token at the beginning of the next end step. Activate only as a sorcery.

Grudge Keeper

Whenever players finish voting, each opponent who voted for a choice you didn't vote for loses 2 life.

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel, Rogue Shadowmage deals 2 damage to them.
−1: Target player discards a card.

Crypt of Agadeem

Crypt of Agadeem enters the battlefield tapped.
{T}: Add {B}.
{2}, {T}: Add {B} for each black creature card in your graveyard.

Court of Ambition

When Court of Ambition enters the battlefield, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Paupers' Cage

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Paupers' Cage deals 2 damage to that player.

Tempt with Immortality

Tempting offer — Return a creature card from your graveyard to the battlefield. Each opponent may return a creature card from their graveyard to the battlefield. For each opponent who does, return a creature card from your graveyard to the battlefield.

Dash Hopes

When you cast this spell, any player may pay 5 life. If a player does, counter Dash Hopes.
Counter target spell.

Ward of Bones

Each opponent who controls more creatures than you can't cast creature spells. The same is true for artifacts and enchantments.
Each opponent who controls more lands than you can't play lands.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Endbringer's Revel

{4}: Return target creature card from a graveyard to its owner's hand. Any player may activate this ability but only as a sorcery.

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Skullcage

At the beginning of each opponent's upkeep, Skullcage deals 2 damage to that player unless they have exactly three or exactly four cards in hand.

Battlefield Butcher

{5}, {T}: Each opponent loses 2 life. This ability costs {1} less to activate for each creature card in your graveyard.

Karn's Sylex

Karn's Sylex enters the battlefield tapped.
Players can't pay life to cast spells or to activate abilities that aren't mana abilities.
{X}, {T}, Exile Karn's Sylex: Destroy each nonland permanent with mana value X or less. Activate only as a sorcery.

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.

Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Bite of the Black Rose

Will of the council — Starting with you, each player votes for sickness or psychosis. If sickness gets more votes, creatures your opponents control get -2/-2 until end of turn. If psychosis gets more votes or the vote is tied, each opponent discards two cards.

Isochron Scepter

Imprint — When Isochron Scepter enters the battlefield, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Swamp

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Nakaya Shade

{B}: Nakaya Shade gets +1/+1 until end of turn unless any player pays {2}.

Cosmos Elixir

At the beginning of your end step, draw a card if your life total is greater than your starting life total. Otherwise, you gain 2 life.

Ebony Owl Netsuke

At the beginning of each opponent's upkeep, if that player has seven or more cards in hand, Ebony Owl Netsuke deals 4 damage to that player.

Wicked Visitor

Whenever an enchantment you control is put into a graveyard from the battlefield, each opponent loses 1 life.

Thought Vessel

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

Angel's Trumpet

All creatures have vigilance.
At the beginning of each player's end step, tap all untapped creatures that player controls that didn't attack this turn. Angel's Trumpet deals damage to the player equal to the number of creatures tapped this way.

Golem's Heart

Whenever a player casts an artifact spell, you may gain 1 life.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Lake of the Dead

If Lake of the Dead would enter the battlefield, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Misers' Cage

At the beginning of each opponent's upkeep, if that player has five or more cards in hand, Misers' Cage deals 2 damage to that player.

Hissing Miasma

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

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment enters the battlefield under your control, each opponent loses 1 life.

Spoils of Evil

For each artifact or creature card in target opponent's graveyard, add {C} and you gain 1 life.

Witch of the Moors

Deathtouch
At the beginning of your end step, if you gained life this turn, each opponent sacrifices a creature and you return up to one target creature card from your graveyard to your hand.

Curse of Fool's Wisdom

Enchant player
Whenever enchanted player draws a card, they lose 2 life and you gain 2 life.
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Garrulous Sycophant

At the beginning of your end step, if you're the monarch, each opponent loses 1 life and you gain 1 life.

Exsanguinate

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

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

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.

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Ultimate Price

Faith of the Devoted

Whenever you cycle or discard a card, you may pay {1}. If you do, each opponent loses 2 life and you gain 2 life.

Glacial Chasm

Cumulative upkeep—Pay 2 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Glacial Chasm enters the battlefield, sacrifice a land.
Creatures you control can't attack.
Prevent all damage that would be dealt to you.

Grave Endeavor

Roll two d10 and choose one result. Return a creature card from your graveyard to the battlefield with a number of +1/+1 counters on it equal to that result. Then each opponent loses X life and you gain X life, where X is the other result.