Omen Machine

Players can't draw cards.
At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Barter in Blood

Each player sacrifices two creatures of their choice.

Duress

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

Disentomb

Return target creature card from your graveyard to your hand.

Gonti, Lord of Luxury

Deathtouch
When Gonti, Lord of Luxury enters, look at the top four cards of target opponent's library, exile one of them face down, then put the rest on the bottom of that library in a random order. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Ambition's Cost

You draw three cards and you lose 3 life.

Mind Sludge

Target player discards a card for each Swamp you control.

Order of Yawgmoth

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Order of Yawgmoth deals damage to a player, that player discards a card.

Wrench Mind

Target player discards two cards unless they discard an artifact card.

Psychic Miasma

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

Sol Ring

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Distress

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

Nausea

All creatures get -1/-1 until end of turn.

Whispers of Emrakul

Target opponent discards a card at random.
Delirium — If there are four or more card types among cards in your graveyard, that player discards two cards at random instead.

Rogue's Passage

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

Arcane Signet

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

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent of their choice 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

Mind Swords

If you control a Swamp, you may sacrifice a creature rather than pay this spell's mana cost.
Each player exiles two cards from their hand.

Megrim

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

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

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.

Syphon Mind

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

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, the Grim 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.)

Rotting Rats

When Rotting Rats enters, 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.)

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Smallpox

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

Plague Wind

Destroy all creatures you don't control. They can't be regenerated.

Pestilence Demon

Flying
{B}: Pestilence Demon deals 1 damage to each creature and each player.

Dark Ritual

Bubbling Muck

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

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Temple of the False God

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

Delirium Skeins

Diabolic Tutor

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

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Innocent Blood

Each player sacrifices a creature of their choice.

Anowon, the Ruin Sage

At the beginning of your upkeep, each player sacrifices a non-Vampire creature of their choice.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Cruel Edict

Target opponent sacrifices a creature of their choice.

Raven's Crime

Target player discards a card.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Swamp

Coercion

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

Shadows of the Past

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{4}{B}: Each opponent loses 2 life and you gain 2 life. Activate only if there are four or more creature cards in your graveyard.

Dark Deal

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

Lightning Greaves

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

Defiant Bloodlord

Flying
Whenever you gain life, target opponent loses that much life.

Ancient Craving

Sensei's Divining Top

{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.

Horrifying Revelation

Target player discards a card, then mills a card.

Ob Nixilis Reignited

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Phyrexian Arena

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

Creeping Dread

At the beginning of your upkeep, each player discards a card. Each opponent who discarded a card that shares a card type with the card you discarded loses 3 life. (Players reveal the discarded cards simultaneously.)

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}

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Cremate

Exile target card from a graveyard.
Draw a card.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

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.

Mind Rot

Unburden

Target player discards two cards.
Cycling {2} ({2}, Discard this card: Draw a card.)