The Haunt of Hightower

Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.

Sadistic Obsession

Enchant creature
Enchanted creature has "{B}, {T}: Put a -1/-1 counter on target creature."

Cruel Sadist

{B}, {T}, Pay 1 life: Put a +1/+1 counter on this creature.
{2}{B}, {T}, Remove X +1/+1 counters from this creature: It deals X damage to target creature.

Ring of Xathrid

{2}: Regenerate equipped creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's black.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Sanguine Bond

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

Cabal Coffers

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

Drivnod, Carnage Dominus

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{B/P}{B/P}, Exile three creature cards from your graveyard: Put an indestructible counter on Drivnod. ({B/P} can be paid with either {B} or 2 life.)

Ob Nixilis, Unshackled

Flying, trample
Whenever an opponent searches their library, that player sacrifices a creature of their choice and loses 10 life.
Whenever another creature dies, put a +1/+1 counter on Ob Nixilis.

Underworld Dreams

Whenever an opponent draws a card, this enchantment deals 1 damage to that player.

Tenured Inkcaster

When this creature enters, put a +1/+1 counter on target creature.
Whenever a creature you control with a +1/+1 counter on it attacks, each opponent loses 1 life and you gain 1 life.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Crumbling Ashes

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Cartouche of Ambition

Enchant creature you control
When this Aura enters, you may put a -1/-1 counter on target creature.
Enchanted creature gets +1/+1 and has lifelink.

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}.

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 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.)

Foundry Hornet

Flying
When this creature enters, if you control a creature with a +1/+1 counter on it, creatures your opponents control get -1/-1 until end of turn.

Ravenous Chupacabra

When this creature enters, destroy target creature an opponent controls.

Festercreep

This creature enters with a +1/+1 counter on it.
{1}{B}, Remove a +1/+1 counter from this creature: All other creatures get -1/-1 until end of turn.

Endless Cockroaches

When this creature dies, return it to its owner's hand.

Agent of the Iron Throne

Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."

Spitting Dilophosaurus

Whenever this creature enters or attacks, put a -1/-1 counter on up to one target creature.
Creatures your opponents control with -1/-1 counters on them can't block.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Hagra Constrictor

This creature enters with two +1/+1 counters on it.
Each creature you control with a +1/+1 counter on it has menace. (A creature with menace can't be blocked except by two or more creatures.)

Go for the Throat

Bloodsoaked Champion

This creature can't block.
Raid — {1}{B}: Return this card from your graveyard to the battlefield. Activate only if you attacked this turn.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

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.

Feast on the Fallen

At the beginning of each upkeep, if an opponent lost life last turn, put a +1/+1 counter on target creature you control.

Lockjaw Snapper

Wither (This deals damage to creatures in the form of -1/-1 counters.)
When this creature dies, put a -1/-1 counter on each creature with a -1/-1 counter on it.

Conductor of Cacophony

This creature enters with two +1/+1 counters on it.
{B}, Remove a +1/+1 counter from this creature: It deals 1 damage to each other creature and each player.

Oathsworn Knight

This creature enters with four +1/+1 counters on it.
This creature attacks each combat if able.
If damage would be dealt to this creature while it has a +1/+1 counter on it, prevent that damage and remove a +1/+1 counter from it.

Slith Bloodletter

Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.
{1}{B}: Regenerate this creature.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: This creature gets +1/+1 until end of turn.

Harbinger of Night

At the beginning of your upkeep, put a -1/-1 counter on each creature.

Unholy Indenture

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control with a +1/+1 counter on it.

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

Grim Affliction

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Gray Merchant of Asphodel

When this creature 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.)

Swamp

Nether Traitor

Haste
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return this card from your graveyard to the battlefield.

Zulaport Cutthroat

Whenever this creature or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Liliana, Death Wielder

+2: Put a -1/-1 counter on up to one target creature.
−3: Destroy target creature with a -1/-1 counter on it.
−10: Return all creature cards from your graveyard to the battlefield.

Vashta Nerada

Indestructible
Shadow (This creature can block or be blocked by only creatures with shadow.)
Morbid — At the beginning of each end step, if a creature died this turn, put a +1/+1 counter on this creature.

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.

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

Desecration Demon

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

Liliana's Influence

Put a -1/-1 counter on each creature you don't control. You may search your library and/or graveyard for a card named Liliana, Death Wielder, reveal it, and put it into your hand. If you search your library this way, shuffle.

Ayara, First of Locthwain

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Hunter of Eyeblights

When this creature enters, put a +1/+1 counter on target creature you don't control.
{2}{B}, {T}: Destroy target creature with a counter on it.

Triskaidekaphobia

At the beginning of your upkeep, choose one —
• Each player with exactly 13 life loses the game, then each player gains 1 life.
• Each player with exactly 13 life loses the game, then each player loses 1 life.

Faerie Bladecrafter

Flying
Whenever one or more Faeries you control deal combat damage to a player, put a +1/+1 counter on this creature.
When this creature dies, each opponent loses X life and you gain X life, where X is its power.

Grimoire of the Dead

{1}, {T}, Discard a card: Put a study counter on Grimoire of the Dead.
{T}, Remove three study counters from Grimoire of the Dead and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.

Nightshade Harvester

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

Pestilence

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

Exquisite Blood

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

Glistening Oil

Enchant creature
Enchanted creature has infect.
At the beginning of your upkeep, put a -1/-1 counter on enchanted creature.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Slaughter Specialist

When this creature enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature.

Dark Ritual

Necroskitter

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

Necrosquito

Flying
This creature enters with two oil counters on it.
This creature gets +1/+1 for each oil counter on it.
Whenever another creature or artifact you control is put into a graveyard from the battlefield, put an oil counter on this creature.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Traveling Plague

Enchant creature
At the beginning of each upkeep, put a plague counter on this Aura.
Enchanted creature gets -1/-1 for each plague counter on this Aura.
When enchanted creature leaves the battlefield, that creature's controller returns this Aura from its owner's graveyard to the battlefield.

Contagion

You may pay 1 life and exile a black card from your hand rather than pay this spell's mana cost.
Distribute two -2/-1 counters among one or two target creatures.

Vampire Scrivener

Flying
Whenever you gain life during your turn, put a +1/+1 counter on this creature.
Whenever you lose life during your turn, put a +1/+1 counter on this creature.

Blood Artist

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

Putrid Goblin

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.)

Tenacious Dead

When this creature dies, you may pay {1}{B}. If you do, return it to the battlefield tapped under its owner's control.

Mer-Ek Nightblade

Outlast {B} ({B}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has deathtouch.

Midnight Banshee

Wither (This deals damage to creatures in the form of -1/-1 counters.)
At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.