Have

Thought Vessel

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

Elderfang Disciple

When Elderfang Disciple enters the battlefield, each opponent discards a card.

Murder

Magus of the Coffers

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

Ravenous Rats

When Ravenous Rats enters the battlefield, target opponent discards a card.

Replace

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Arcane Signet

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

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.)

Mortuary Mire

Mortuary Mire enters the battlefield tapped.
When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Culling the Weak

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

Corrupt Court Official

When Corrupt Court Official enters the battlefield, target opponent discards a card.

Mutilate

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

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.

Don't Have

Rotting Rats

When Rotting Rats enters the battlefield, each player discards a card.
Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Lightning Greaves

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

Slum Reaper

When Slum Reaper enters the battlefield, each player sacrifices a creature.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Vicious Rumors

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

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Dark Ritual

Ostracize

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

Abyssal Specter

Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.

Sign in Blood

Target player draws two cards and loses 2 life.

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Tasigur's Cruelty

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Each opponent discards two cards.

Mire's Toll

Target player reveals a number of cards from their hand equal to the number of Swamps you control. You choose one of them. That player discards that card.

Psychic Miasma

Target player discards a card. If a land card is discarded this way, return Psychic Miasma to its owner's hand.

Castle Locthwain

Castle Locthwain enters the battlefield 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.

Doom Blade

Dark Deal

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

Sol Ring

Elvish Doomsayer

When Elvish Doomsayer dies, each opponent discards a card.

Arterial Flow

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

Smallpox

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

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Last Rites

Discard any number of cards. Target player reveals their hand, then you choose a nonland card from it for each card discarded this way. That player discards those cards.

Burglar Rat

When Burglar Rat enters the battlefield, each opponent discards a card.

Mind Stone

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

Fleshbag Marauder

When Fleshbag Marauder enters the battlefield, each player sacrifices a creature.

Distress

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

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

Bottomless Pit

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

Syphon Mind

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

The Raven Man

At the beginning of each end step, if a player discarded a card this turn, create a 1/1 black Bird creature token with flying and "This creature can't block."
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Horrifying Revelation

Target player discards a card, then mills 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.

Drainpipe Vermin

When Drainpipe Vermin dies, you may pay {B}. If you do, target player discards a card.

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.

Black Market Connections

At the beginning of your precombat main phase, choose one or more —
• Sell Contraband — Create a Treasure token. You lose 1 life.
• Buy Information — Draw a card. You lose 2 life.
• Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Demon's Disciple

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

Oppression

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

Death Cloud

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

Necrogen Mists

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

Delirium Skeins

Swiftfoot Boots

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

Victim of Night

Destroy target non-Vampire, non-Werewolf, non-Zombie creature.

Plaguecrafter

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

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.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Duress

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

Liliana's Triumph

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

Innocent Blood

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.

Make an Example

Each opponent separates the creatures they control into two piles. For each opponent, you choose one of their piles. Each opponent sacrifices the creatures in their chosen pile. (Piles can be empty.)

Swamp

Toll of the Invasion

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

Fell Specter

Flying
When Fell Specter enters the battlefield, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.

Liliana's Specter

Flying
When Liliana's Specter enters the battlefield, each opponent discards a card.

Braids's Frightful Return

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may sacrifice a creature. If you do, each opponent discards a card.
II — Return target creature card from your graveyard to your hand.
III — Target opponent may sacrifice a nonland, nontoken permanent. If they don't, they lose 2 life and you draw a card.