Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Tinybones, Bauble Burglar

Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it.
During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells.
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Ripples of Undeath

At the beginning of your first main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Bottomless Pit

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

Necrodominance

Skip your draw step.
At the beginning of your end step, you may pay any amount of life. If you do, draw that many cards.
Your maximum hand size is five.
If a card or token would be put into your graveyard from anywhere, exile it instead.

Magus of the Coffers

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

Cunning Lethemancer

At the beginning of your upkeep, each player discards a card.

Megrim

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

Call to the Netherworld

Return target black creature card from your graveyard to your hand.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Larceny

Whenever a creature you control deals combat damage to a player, that player discards a card.

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Delirium Skeins

Nyx Lotus

Nyx Lotus enters tapped.
{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.)

Hymn to Tourach

Target player discards two cards at random.

Funeral Charm

Choose one —
• Target player discards a card.
• Target creature gets +2/-1 until end of turn.
• Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)

Pilfer

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

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.

Raiders' Wake

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.

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Duress

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

Witch's Cottage

({T}: Add {B}.)
This land enters tapped unless you control three or more other Swamps.
When this land enters untapped, you may put target creature card from your graveyard on top of your library.

Don't Have

Dark Ritual

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.

Sol Ring

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.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Dark Deal

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

Syphon Mind

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

Mindslicer

When this creature dies, each player discards their hand.

Jet Medallion

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Culling the Weak

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

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.

Liliana Vess

+1: Target player discards a card.
−2: Search your library for a card, then shuffle and put that card on top.
−8: Put all creature cards from all graveyards onto the battlefield under your control.

Fell Specter

Flying
When this creature enters, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.

Rush of Dread

Spree (Choose one or more additional costs.)
+ {1} — Target opponent sacrifices half the creatures they control of their choice, rounded up.
+ {2} — Target opponent discards half the cards in their hand, rounded up.
+ {2} — Target opponent loses half their life, rounded up.

Oppression

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

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.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Entropic Battlecruiser

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 8+.)
1+ | Whenever an opponent discards a card, they lose 3 life.
8+ | Flying, deathtouch
Whenever this Spacecraft attacks, each opponent discards a card. Each opponent who can't loses 3 life.