Nighthowler

Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Unhallowed Pact

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Damnation

Destroy all creatures. They can't be regenerated.

Duskmantle Guildmage

{1}{U}{B}: Whenever a card is put into an opponent's graveyard from anywhere this turn, that player loses 1 life.
{2}{U}{B}: Target player mills two cards.

Doom Blade

Evolving Wilds

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

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.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Tribute to Hunger

Target opponent sacrifices a creature of their choice. You gain life equal to that creature's toughness.

Sol Ring

Nephalia Smuggler

{3}{U}, {T}: Exile another target creature you control, then return that card to the battlefield under your control.

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

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.

Cast Down

Dying Wish

Enchant creature you control
When enchanted creature dies, target player loses X life and you gain X life, where X is its power.

Dismal Backwater

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

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Captain N'ghathrod

Horrors you control have menace.
Whenever a Horror you control deals combat damage to a player, that player mills that many cards.
At the beginning of your end step, choose target artifact or creature card in an opponent's graveyard that was put there from their library this turn. Put it onto the battlefield under your control.

Disciple of Griselbrand

{1}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Guiltfeeder

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Guiltfeeder attacks and isn't blocked, defending player loses 1 life for each card in their graveyard.

Claustrophobia

Enchant creature
When Claustrophobia enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Mesmeric Fiend

When Mesmeric Fiend enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When Mesmeric Fiend leaves the battlefield, return the exiled card to its owner's hand.

Venarian Glimmer

Target player reveals their hand. You choose a nonland card with mana value X or less from it. That player discards that card.

Grell Philosopher

Aberrant Tinkering — When Grell Philosopher enters and at the beginning of your upkeep, each Horror you control gains all activated abilities of target artifact an opponent controls until end of turn. You may spend blue mana as though it were mana of any color to activate those abilities.

Mind Rot

Darkwater Catacombs

Temple of the False God

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

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature of their choice.

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.

Turn Aside

Counter target spell that targets a permanent you control.

Soul Salvage

Return up to two target creature cards from your graveyard to your hand.

Ravenous Rats

When Ravenous Rats enters, target opponent discards a card.

Zellix, Sanity Flayer

Hive Mind — Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.
{1}, {T}: Target player mills three cards.
Choose a Background (You can have a Background as a second commander.)

Arcane Signet

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

Divination

Nemesis of Reason

Whenever Nemesis of Reason attacks, defending player mills ten cards.

Gollum, Scheming Guide

Whenever Gollum, Scheming Guide attacks, look at the top two cards of your library, put them back in any order, then choose land or nonland. An opponent guesses whether the top card of your library is the chosen kind. Reveal that card. If they guessed right, remove Gollum from combat. Otherwise, you draw a card and Gollum can't be blocked this turn.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Mind Stone

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

Faceless Butcher

When Faceless Butcher enters, exile another target creature.
When Faceless Butcher leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Mire's Toll

Target player reveals a number of cards from their hand equal to the number of Swamps you control. You choose one of them. That player discards that card.

Liturgy of Blood

Caligo Skin-Witch

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
When Caligo Skin-Witch enters, if it was kicked, each opponent discards two cards.

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.)

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Innocent Blood

Each player sacrifices a creature of their choice.

Swamp

Essence Scatter

Tormented Thoughts

As an additional cost to cast this spell, sacrifice a creature.
Target player discards a number of cards equal to the sacrificed creature's power.

Psychic Strike

Counter target spell. Its controller mills two cards.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Marsh Casualties

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Creatures target player controls get -1/-1 until end of turn. If this spell was kicked, those creatures get -2/-2 until end of turn instead.

Disentomb

Return target creature card from your graveyard to your hand.

Hideous End

Destroy target nonblack creature. Its controller loses 2 life.

Murder

Drainpipe Vermin

When Drainpipe Vermin dies, you may pay {B}. If you do, target player discards a card.

Annul

Counter target artifact or enchantment spell.

Evanescent Intellect

Enchant creature
Enchanted creature has "{1}{U}, {T}: Target player mills three cards."

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Defiler of Flesh

Menace
As an additional cost to cast black permanent spells, you may pay 2 life. Those spells cost {B} less to cast if you paid life this way. This effect reduces only the amount of black mana you pay.
Whenever you cast a black permanent spell, target creature you control gets +1/+1 and gains menace until end of turn.

Dimir Charm

Choose one —
• Counter target sorcery spell.
• Destroy target creature with power 2 or less.
• Look at the top three cards of target player's library. Put one back and the rest into that player's graveyard.

Cancel

Extract from Darkness

Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.

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.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Negate

Island

Viper's Kiss

Enchant creature
Enchanted creature gets -1/-1, and its activated abilities can't be activated.

Encrust

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step and its activated abilities can't be activated.