Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Spawning Pool

This land enters tapped.
{T}: Add {B}.
{1}{B}: This land becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

No Mercy

Whenever a creature deals damage to you, destroy it.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: This artifact deals 50 damage to any target.

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

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.

Mishra's Factory

{T}: Add {C}.
{1}: This land becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Swamp

Blood Artist

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

Liliana, Defiant Necromancer

+2: Each player discards a card.
−X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.
−8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Liliana, Heretical Healer

Lifelink
Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

Liliana, Heretical Healer // Liliana, Defiant Necromancer

Damnation

Destroy all creatures. They can't be regenerated.

Epic Downfall

Exile target creature with mana value 3 or greater.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When this creature dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Diamond Mare

As this creature enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

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.

Drownyard Temple

{T}: Add {C}.
{3}: Return this card from your graveyard to the battlefield tapped.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying 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.)

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Font of Agonies

Whenever you pay life, put that many blood counters on this enchantment.
{1}{B}, Remove four blood counters from this enchantment: Destroy target creature.

Falkenrath Noble

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

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Thrull Parasite

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.)
{T}, Pay 2 life: Remove a counter from target nonland permanent.

Memorial to Folly

This land enters tapped.
{T}: Add {B}.
{2}{B}, {T}, Sacrifice this land: Return target creature card from your graveyard to your hand.

Geth, Lord of the Vault

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

Prism Ring

As this artifact enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Animate Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Defile

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

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

Sanctum of Eternity

{T}: Add {C}.
{2}, {T}: Return target commander you own from the battlefield to your hand. Activate only during your turn.

Evolving Wilds

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

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.)

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.)

Detection Tower

{T}: Add {C}.
{1}, {T}: Until end of turn, your opponents and creatures your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Armillary Sphere

{2}, {T}, Sacrifice this artifact: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Sol Ring

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Exsanguinate

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

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Reliquary Tower

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

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Live Fast

You draw two cards, lose 2 life, and get {E}{E} (two energy counters).

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Liliana's Standard Bearer

Flash
When this creature enters, draw X cards, where X is the number of creatures that died under your control this turn.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

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.

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

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.)

Noxious Gearhulk

Menace
When this creature enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Cavalier of Night

Lifelink
When this creature enters, you may sacrifice another creature. When you do, destroy target creature an opponent controls.
When this creature dies, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Zombie Infestation

Discard two cards: Create a 2/2 black Zombie creature token.

Lord of Lineage

Flying
Other Vampire creatures you control get +2/+2.
{T}: Create a 2/2 black Vampire creature token with flying.

Bloodline Keeper

Flying
{T}: Create a 2/2 black Vampire creature token with flying.
{B}: Transform this creature. Activate only if you control five or more Vampires.

Bloodline Keeper // Lord of Lineage

Cabal Stronghold

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

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Temple of the False God

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

Phyrexian Tower

{T}: Add {C}.
{T}, Sacrifice a creature: Add {B}{B}.

Demonic Tutor

Doomed Necromancer

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

Cabal Ritual

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

Sanitarium Skeleton

{2}{B}: Return this card from your graveyard to your hand.

Dakmor Salvage

This land enters tapped.
{T}: Add {B}.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever this artifact becomes untapped, you may pay {2}. If you do, draw a card.

Aether Hub

When this land enters, you get {E} (an energy counter).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Open the Graves

Whenever a nontoken creature you control dies, create a 2/2 black Zombie creature token.

Night's Whisper

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.

Polluted Mire

This land enters tapped.
{T}: Add {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Terramorphic Expanse

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Command Tower

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

Ashnod's Altar

Sign in Blood

Target player draws two cards and loses 2 life.

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.)

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Dark Ritual

Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)