Mutilate

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

Chainer, Dementia Master

All Nightmares get +1/+1.
{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.
When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Soulless One

Soulless One's power and toughness are each equal to the number of Zombies on the battlefield plus the number of Zombie cards in all graveyards.

Blackmail

Target player reveals three cards from their hand and you choose one of them. That player discards that card.

Rotlung Reanimator

Whenever Rotlung Reanimator or another Cleric dies, create a 2/2 black Zombie creature token.

Boneknitter

{1}{B}: Regenerate target Zombie.
Morph {2}{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.)

Cabal Coffers

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

Shepherd of Rot

{T}: Each player loses 1 life for each Zombie on the battlefield.

Wretched Anurid

Whenever another creature enters, you lose 1 life.

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Doomed Necromancer

{B}, {T}, Sacrifice Doomed Necromancer: Return target creature card from your graveyard to the battlefield.

Swamp

Disciple of Malice

Protection from white
Cycling {2} ({2}, Discard this card: Draw a card.)

Mind Sludge

Target player discards a card for each Swamp you control.

Visara the Dreadful

Flying
{T}: Destroy target creature. It can't be regenerated.

Carrion Wurm

Whenever Carrion Wurm attacks or blocks, any player may exile three cards from their graveyard. If a player does, Carrion Wurm assigns no combat damage this turn.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

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.

Frightshroud Courier

You may choose not to untap Frightshroud Courier during your untap step.
{2}{B}, {T}: Target Zombie creature gets +2/+2 and has fear for as long as Frightshroud Courier remains tapped. (It can't be blocked except by artifact creatures and/or black creatures.)

Anurid Murkdiver

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Cabal Ritual

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

Haunted Cadaver

Whenever Haunted Cadaver deals combat damage to a player, you may sacrifice it. If you do, that player discards three cards.
Morph {1}{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.)

Screeching Buzzard

Flying
When Screeching Buzzard dies, each opponent discards a card.

Cover of Darkness

As Cover of Darkness enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Fallen Cleric

Protection from Clerics
Morph {4}{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.)

Cruel Revival

Destroy target non-Zombie creature. It can't be regenerated. Return up to one target Zombie card from your graveyard to your hand.

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Oversold Cemetery

At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

Aphetto Dredging

Return up to three target creature cards of the creature type of your choice from your graveyard to your hand.

Feeding Frenzy

Target creature gets -X/-X until end of turn, where X is the number of Zombies on the battlefield.

Headhunter

Whenever Headhunter deals combat damage to a player, that player discards a card.
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.)

Gravespawn Sovereign

Tap five untapped Zombies you control: Put target creature card from a graveyard onto the battlefield under your control.

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.

Organ Grinder

{T}, Exile three cards from your graveyard: Target player loses 3 life.

Nantuko Shade

{B}: Nantuko Shade gets +1/+1 until end of turn.

Severed Legion

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)