Skulduggery

Until end of turn, target creature you control gets +1/+1 and target creature an opponent controls gets -1/-1.

Pilfer

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

Liliana's Triumph

Each opponent sacrifices a creature of their choice. If you control a Liliana planeswalker, each opponent also discards a card.

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Mire in Misery

Each opponent sacrifices a creature or enchantment of their choice.

Mourning

Enchant creature
Enchanted creature gets -2/-0.
{B}: Return Mourning to its owner's hand.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

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.)

Lord of the Accursed

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

Gollum's Bite

Target creature gets -2/-2 until end of turn.
{3}{B}, Exile Gollum's Bite from your graveyard: The Ring tempts you. Activate only as a sorcery.

Necrotic Hex

Each player sacrifices six creatures of their choice. You create six tapped 2/2 black Zombie creature tokens.

Cemetery Reaper

Other Zombie creatures you control get +1/+1.
{2}{B}, {T}: Exile target creature card from a graveyard. Create a 2/2 black Zombie creature token.

Feebleness

Flash
Enchant creature
Enchanted creature gets -2/-1.

Gisa, the Hellraiser

Ward—{2}, Pay 2 life.
Skeletons and Zombies you control get +1/+1 and have menace.
Whenever you commit a crime, create two tapped 2/2 blue and black Zombie Rogue creature tokens. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Desert's Due

Target creature gets -2/-2 until end of turn. It gets an additional -1/-1 until end of turn for each Desert you control.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Hero's Downfall

Commander's Sphere

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

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Arcane Signet

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

Swamp

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Vizier of the Scorpion

When Vizier of the Scorpion enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have deathtouch.

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Minion's Return

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

Nurgle's Rot

Enchant creature an opponent controls
When enchanted creature dies, return Nurgle's Rot to its owner's hand and you create a 1/3 black Demon creature token named Plaguebearer of Nurgle.

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Murder

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on Champion of the Perished.

Defile

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

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Ghoulcaller Gisa

{B}, {T}, Sacrifice another creature: Create X 2/2 black Zombie creature tokens, where X is the sacrificed creature's power.

Innocent Blood

Each player sacrifices a creature of their choice.

Diabolic Edict

Target player sacrifices a creature of their choice.

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.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

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.)

Dark Ritual

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.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.