Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel deals 2 damage to them.
−1: Target player discards a card.

Abyssal Nocturnus

Whenever an opponent discards a card, this creature gets +2/+2 and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Outpost Siege

As this enchantment enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, this enchantment deals 1 damage to any target.

Sire of Insanity

At the beginning of each end step, each player discards their hand.

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Rankle, Master of Pranks

Flying, haste
Whenever Rankle 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 of their choice.

Hero's Downfall

Wheel of Fate

Suspend 4—{1}{R} (Rather than cast this card from your hand, pay {1}{R} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Each player discards their hand, then draws seven cards.

Hellfire Mongrel

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, this creature deals 2 damage to that player.

Fiery Temper

Fiery Temper deals 3 damage to any target.
Madness {R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Lavaborn Muse

At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, this creature deals 3 damage to that player.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

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.

Geth's Grimoire

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

Magus of the Wheel

{1}{R}, {T}, Sacrifice this creature: Each player discards their hand, then draws seven cards.

Swamp

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Terminate

Destroy target creature. It can't be regenerated.

Rakdos's Return

Rakdos's Return deals X damage to target opponent or planeswalker. That player or that planeswalker's controller discards X cards.

Delirium Skeins

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Asylum Visitor

At the beginning of each player's upkeep, if that player has no cards in hand, you draw a card and you lose 1 life.
Madness {1}{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.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Theater of Horrors

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with this enchantment.
{3}{R}: This enchantment deals 1 damage to target opponent or planeswalker.

Dreadbore

Rotting Rats

When this creature 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.)

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Mountain

Megrim

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

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.

Necrogen Mists

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

Davriel's Shadowfugue

Target player discards two cards and loses 2 life.

Angrath, the Flame-Chained

+1: Each opponent discards a card and loses 2 life.
−3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.
−8: Each opponent loses life equal to the number of cards in their graveyard.

Rakdos Signet

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.

Duress

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

Blood Scrivener

If you would draw a card while you have no cards in hand, instead you draw two cards and you lose 1 life.

The Haunt of Hightower

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.

Shrieking Affliction

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Bottomless Pit

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