Whenever an opponent discards a card, Abyssal Nocturnus gets +2/+2 and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
2 /
2
{2}{B}{B}
Abyssal Specter
Creature - Specter
Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.
2 /
3
{1}{U/B}{U/B}
Ashiok, Dream Render
Legendary Planeswalker - Ashiok
Spells and abilities your opponents control can't cause their controller to search their library.
-1: Target player mills four cards. Then exile each opponent's graveyard.
L:
5
{3}{B}{B}
Banshee of the Dread Choir
Creature - Spirit
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Banshee of the Dread Choir deals combat damage to a player, that player discards a card.
4 /
4
{5}
Bargaining Table
Artifact
{X}, {T}: Draw a card. X is the number of cards in an opponent's hand.
{2}{U}{B}
Barrin's Spite
Sorcery
Choose two target creatures controlled by the same player. Their controller chooses and sacrifices one of them. Return the other to its owner's hand.
{4}{B}{B}
Capital Punishment
Sorcery
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.
{2}
Charcoal Diamond
Artifact
Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.
--
Choked Estuary
Land
As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.
{T}: Add {U} or {B}.
--
City of Brass
Land
Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.
--
Command Tower
Land
{T}: Add one mana of any color in your commander's color identity.
{4}
Cursed Rack
Artifact
As Cursed Rack enters the battlefield, choose an opponent.
The chosen player's maximum hand size is four.
{2}{B}
Dark Deal
Sorcery
Each player discards all the cards in their hand, then draws that many cards minus one.
--
Darkwater Catacombs
Land
{1}, {T}: Add {U}{B}.
{2}{B}
Davriel, Rogue Shadowmage
Legendary Planeswalker - Davriel
At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel, Rogue Shadowmage deals 2 damage to them.
-1: Target player discards a card.
L:
3
{1}{U}{B}
Dimir Cutpurse
Creature - Spirit
Whenever Dimir Cutpurse deals combat damage to a player, that player discards a card and you draw a card.
2 /
2
{2}
Dimir Signet
Artifact
{1}, {T}: Add {U}{B}.
{3}{U/B}{U/B}
Dire Undercurrents
Enchantment
Whenever a blue creature enters the battlefield under your control, you may have target player draw a card.
Whenever a black creature enters the battlefield under your control, you may have target player discard a card.
{U/B}
Dream Salvage
Instant
Draw cards equal to the number of cards target opponent discarded this turn.
{U}{B}
Duskmantle Guildmage
Creature - Human Wizard
{1}{U}{B}: Whenever a card is put into an opponent's graveyard from anywhere this turn, that player loses 1 life.
{2}{U}{B}: Target player mills two cards.
2 /
2
--
Evolving Wilds
Land
{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
--
Exotic Orchard
Land
{T}: Add one mana of any color that a land an opponent controls could produce.
{3}{B}
Fell Specter
Creature - Specter
Flying
When Fell Specter enters the battlefield, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.
1 /
3
{2}
Fellwar Stone
Artifact
{T}: Add one mana of any color that a land an opponent controls could produce.
--
Field of Ruin
Land
{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.
--
Forbidden Orchard
Land
{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.
--
Geier Reach Sanitarium
Legendary Land
{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.
{4}
Geth's Grimoire
Artifact
Whenever an opponent discards a card, you may draw a card.
--
Ghost Quarter
Land
{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.
{1}
Glasses of Urza
Artifact
{T}: Look at target player's hand.
{2}{B}
Go Blank
Sorcery
Target player discards two cards. Then exile that player's graveyard.
--
Grixis Panorama
Land
{T}: Add {C}.
{1}, {T}, Sacrifice Grixis Panorama: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.
{5}{B}{B}
Hedonist's Trove
Enchantment
When Hedonist's Trove enters the battlefield, exile target opponent's graveyard.
You may play lands from among cards exiled with Hedonist's Trove.
You may cast spells from among cards exiled with Hedonist's Trove. You can't cast more than one spell this way each turn.
{5}{B}{B}
Hollowborn Barghest
Creature - Demon Dog
At the beginning of your upkeep, if you have no cards in hand, each opponent loses 2 life.
At the beginning of each opponent's upkeep, if that player has no cards in hand, they lose 2 life.
7 /
6
{B}{B}
Hymn to Tourach
Sorcery
Target player discards two cards at random.
{1}{B}{B}
Hypnotic Specter
Creature - Specter
Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.
2 /
2
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
{1}{B}
Liliana's Caress
Enchantment
Whenever an opponent discards a card, that player loses 2 life.
--
Mana Confluence
Land
{T}, Pay 1 life: Add one mana of any color.
{1}
Mana Vault
Artifact
Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.
{2}{B}
Megrim
Enchantment
Whenever an opponent discards a card, Megrim deals 2 damage to that player.
{U}
Mind Bomb
Sorcery
Each player may discard up to three cards. Mind Bomb deals damage to each player equal to 3 minus the number of cards they discarded this way.
{X}{B}
Mind Twist
Sorcery
Target player discards X cards at random.
{1}{U}{B}
Mistvein Borderpost
Artifact
You may pay {1} and return a basic land you control to its owner's hand rather than pay this spell's mana cost.
Mistvein Borderpost enters the battlefield tapped.
{T}: Add {U} or {B}.
{U}
Mystic Remora
Enchantment
Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.
{1}{U}{U}
Narset, Parter of Veils
Legendary Planeswalker - Narset
Each opponent can't draw more than one card each turn.
-2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
L:
5
{3}{U}{B}
Nebuchadnezzar
Legendary Creature - Human Wizard
{X}, {T}: Choose a card name. Target opponent reveals X cards at random from their hand. Then that player discards all cards with that name revealed this way. Activate only during your turn.
3 /
3
{1}{B}
Nezumi Shortfang
Creature - Rat Rogue
{1}{B}, {T}: Target opponent discards a card. Then if that player has no cards in hand, flip Nezumi Shortfang.
1 /
1
--
Stabwhisker the Odious
Legendary Creature - Rat Shaman
At the beginning of each opponent's upkeep, that player loses 1 life for each card fewer than three in their hand.
1 /
1
{4}
Noetic Scales
Artifact
At the beginning of each player's upkeep, return to its owner's hand each creature that player controls with power greater than the number of cards in their hand.
{2}{U}{B}
Notion Thief
Creature - Human Rogue
Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.
3 /
1
{1}{B}{B}
Nyxathid
Creature - Elemental
As Nyxathid enters the battlefield, choose an opponent.
Nyxathid gets -1/-1 for each card in the chosen player's hand.
7 /
7
{3}
Paupers' Cage
Artifact
At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Paupers' Cage deals 2 damage to that player.
{1}{U}{B}
Perplex
Instant
Counter target spell unless its controller discards their hand.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)
{2}{B}
Plague Reaver
Creature - Beast
At the beginning of your end step, sacrifice each other creature you control.
Discard two cards, Sacrifice Plague Reaver: Choose target opponent. Return Plague Reaver to the battlefield under that player's control at the beginning of their next upkeep.
6 /
5
{B}
Quest for the Nihil Stone
Enchantment
Whenever an opponent discards a card, you may put a quest counter on Quest for the Nihil Stone.
At the beginning of each opponent's upkeep, if that player has no cards in hand and Quest for the Nihil Stone has two or more quest counters on it, you may have that player lose 5 life.
{4}
Rackling
Artifact Creature - Phyrexian Construct
At the beginning of each opponent's upkeep, Rackling deals X damage to that player, where X is 3 minus the number of cards in their hand.
2 /
2
{2}{B}{B}
Rag Man
Creature - Human Minion
{B}{B}{B}, {T}: Target opponent reveals their hand and discards a creature card at random. Activate only during your turn.
2 /
1
{3}{B}
Raiders' Wake
Enchantment
Whenever an opponent discards a card, that player loses 2 life.
Raid -- At the beginning of your end step, if you attacked this turn, target opponent discards a card.
--
Reflecting Pool
Land
{T}: Add one mana of any type that a land you control could produce.
--
River of Tears
Land
{T}: Add {U}. If you played a land this turn, add {B} instead.
{4}{U}{U}
River's Rebuke
Sorcery
Return all nonland permanents target player controls to their owner's hand.
--
Rogue's Passage
Land
{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.
{4}{B}{B}
Scythe Specter
Creature - Specter
Flying
Whenever Scythe Specter deals combat damage to a player, each opponent discards a card. Each player who discarded a card with the highest mana value among cards discarded this way loses life equal to that mana value.
4 /
4
{1}
Sensei's Divining Top
Artifact
{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.
{B}
Shrieking Affliction
Enchantment
At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.
{4}
Skullcage
Artifact
At the beginning of each opponent's upkeep, Skullcage deals 2 damage to that player unless they have exactly three or exactly four cards in hand.
{1}
Sol Ring
Artifact
{T}: Add {C}{C}.
--
Spire of Industry
Land
{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only if you control an artifact.
{2}{B}
Stronghold Rats
Creature - Rat
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.
2 /
1
--
Sunken Hollow
Land - Island Swamp
({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
--
Swamp
Basic Land - Swamp
({T}: Add {B}.)
{3}{B}
Syphon Mind
Sorcery
Each other player discards a card. You draw a card for each card discarded this way.
{2}
Talisman of Dominance
Artifact
{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.
{U}
Telepathy
Enchantment
Your opponents play with their hands revealed.
--
Terramorphic Expanse
Land
{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{4}{B}{B}
The Haunt of Hightower
Legendary Creature - Vampire
Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.
3 /
3
{1}
The Rack
Artifact
As The Rack enters the battlefield, choose an opponent.
At the beginning of the chosen player's upkeep, The Rack deals X damage to that player, where X is 3 minus the number of cards in their hand.
{U}{B}
Thoughtcutter Agent
Artifact Creature - Human Rogue
{U}{B}, {T}: Target player loses 1 life and reveals their hand.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.
{3}{B}
Unnerve
Sorcery
Each opponent discards two cards.
{2}{U}
Wandering Eye
Creature - Illusion
Flying
Players play with their hands revealed.
1 /
3
{1}{B}
Waste Not
Enchantment
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.
--
Watery Grave
Land - Island Swamp
({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.
{1}
Wayfarer's Bauble
Artifact
{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
{3}
Wheel of Torture
Artifact
At the beginning of each opponent's upkeep, Wheel of Torture deals X damage to that player, where X is 3 minus the number of cards in their hand.
{2}{U}
Windfall
Sorcery
Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.
{3}{U}
Zur's Weirding
Enchantment
Players play with their hands revealed.
If a player would draw a card, they reveal it instead. Then any other player may pay 2 life. If a player does, put that card into its owner's graveyard. Otherwise, that player draws a card.
{2}{B}{B}
Locust Miser
Creature - Rat Shaman
Each opponent's maximum hand size is reduced by two.
2 /
2
{1}{B}{B}
Master of the Feast
Enchantment Creature - Demon
Flying
At the beginning of your upkeep, each opponent draws a card.
5 /
5
{B}
Mire's Toll
Sorcery
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.
{1}
Nihil Spellbomb
Artifact
{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.
{4}
Otherworld Atlas
Artifact
{T}: Put a charge counter on Otherworld Atlas.
{T}: Each player draws a card for each charge counter on Otherworld Atlas.
{2}{B}{B}
Sangromancer
Creature - Vampire Shaman
Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.
3 /
3
{4}{B}
The Eldest Reborn
Enchantment - Saga
(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.
{4}{B}{B}
Thought Distortion
Sorcery
This spell can't be countered.
Target opponent reveals their hand. Exile all noncreature, nonland cards from that player's hand and graveyard.
{4}{B}{B}
Urgoros, the Empty One
Legendary Creature - Specter
Flying
Whenever Urgoros, the Empty One deals combat damage to a player, that player discards a card at random. If the player can't, you draw a card.