Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature.

Words of Waste

{1}: The next time you would draw a card this turn, each opponent discards a card instead.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Court of Ambition

When Court of Ambition enters, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Geier Reach Sanitarium

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Necrogoyf

Necrogoyf's power is equal to the number of creature cards in all graveyards.
At the beginning of each player's upkeep, that player discards a card.
Madness {1}{B}{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.)

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Tinybones, Trinket Thief

At the beginning of each end step, if an opponent discarded a card this turn, you draw a card and you lose 1 life.
{4}{B}{B}: Each opponent with no cards in hand loses 10 life.

Jet Medallion

Black spells you cast cost {1} less to cast.

Shadowgrange Archfiend

When Shadowgrange Archfiend enters, each opponent sacrifices a creature with the greatest power among creatures they control. You gain life equal to the greatest power among creatures sacrificed this way.
Madness—{2}{B}, Pay 8 life. (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Delirium Skeins

Malakir Mire

Malakir Mire enters tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

Necrogen Mists

At the beginning of each player's upkeep, that player discards a card.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Liliana, Waker of the Dead

+1: Each player discards a card. Each opponent who can't loses 3 life.
−3: Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard.
−7: You get an emblem with "At the beginning of combat on your turn, put target creature card from a graveyard onto the battlefield under your control. It gains haste."

Syphon Mind

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

Grief

Menace
When Grief enters, target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Evoke—Exile a black card from your hand.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker.

Mire in Misery

Each opponent sacrifices a creature or enchantment.

Mind Rake

Target player discards two cards.
Overload {1}{B} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Cabal Coffers

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

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.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Sol Ring

Thought Vessel

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

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Capital Punishment

Council's dilemma — Starting with you, each player votes for death or taxes. Each opponent sacrifices a creature for each death vote and discards a card for each taxes vote.

Mindslicer

When Mindslicer dies, each player discards their hand.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Smokestack

At the beginning of your upkeep, you may put a soot counter on Smokestack.
At the beginning of each player's upkeep, that player sacrifices a permanent for each soot counter on Smokestack.

Mind Stone

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

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.)

Oppression

Whenever a player casts a spell, that player discards a card.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Liliana's Triumph

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

Tourach, Dread Cantor

Kicker {B}{B} (You may pay an additional {B}{B} as you cast this spell.)
Protection from white
Whenever an opponent discards a card, put a +1/+1 counter on Tourach, Dread Cantor.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Dark Ritual

Arterial Flow

Each opponent discards two cards. If you control a Vampire, each opponent loses 2 life and you gain 2 life.

Rankle, Master of Pranks

Flying, haste
Whenever Rankle, Master of Pranks deals combat damage to a player, choose any number —
• Each player discards a card.
• Each player loses 1 life and draws a card.
• Each player sacrifices a creature.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Swamp

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

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}.

Burglar Rat

When Burglar Rat enters, each opponent discards a card.

Elderfang Disciple

When Elderfang Disciple enters, each opponent discards a card.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control, then sacrifices a third of the lands they control. Round up each time.

Arcane Signet

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

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature.

Death Cloud

Each player loses X life, discards X cards, sacrifices X creatures, then sacrifices X lands.

Charcoal Diamond

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

Torment of Hailfire

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

The Eldest Reborn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature. If you have the city's blessing, instead each opponent sacrifices half the creatures they control, rounded up.

Cabal Stronghold

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

Awaken the Erstwhile

Each player discards all the cards in their hand, then creates that many 2/2 black Zombie creature tokens.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Phyrexian Obliterator

Trample
Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control. Round up each time.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

Smallpox

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

Professor Onyx

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 2 life and you gain 2 life.
+1: You lose 1 life. Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
−3: Each opponent sacrifices a creature with the greatest power among creatures that player controls.
−8: Each opponent may discard a card. If they don't, they lose 3 life. Repeat this process six more times.