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.

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

Ordeal of Erebos

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice this Aura.
When you sacrifice this Aura, target player discards two cards.

Cutthroat Maneuver

Up to two target creatures each get +1/+1 and gain lifelink until end of turn.

Mind Sludge

Target player discards a card for each Swamp you control.

Mind Drain

Target opponent discards two cards, mills a card, and loses 1 life. You gain 1 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Gwenom, Remorseless

Deathtouch, lifelink
Whenever Gwenom attacks, until end of turn, you may look at the top card of your library any time and you may play cards 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.

Greed's Gambit

When this enchantment enters, you draw three cards, gain 6 life, and create three 2/1 black Bat creature tokens with flying.
At the beginning of your end step, you discard a card, lose 2 life, and sacrifice a creature.
When this enchantment leaves the battlefield, you discard three cards, lose 6 life, and sacrifice three creatures.

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.

Umbral Collar Zealot

Sacrifice another creature or artifact: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mycosynth Wellspring

When this artifact enters or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Corpse Traders

{2}{B}, Sacrifice a creature: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.

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.

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 of their choice. If they don't, they lose 2 life and you draw a card.

Sadistic Hypnotist

Sacrifice a creature: Target player discards two cards. Activate only as a sorcery.

Drainpipe Vermin

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

Mire's Malice

Target opponent discards two cards.
Awaken 3—{5}{B} (If you cast this spell for {5}{B}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Mental Vapors

Target player discards a card.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Tinybones Joins Up

When Tinybones Joins Up enters, any number of target players each discard a card.
Whenever a legendary creature you control enters, any number of target players each mill a card and lose 1 life.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

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 token can't block."
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Mind Slash

{B}, Sacrifice a creature: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.

Scorpion's Sting

Target creature gets -3/-3 until end of turn.

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.

Sol Ring

Slate Street Ruffian

Whenever this creature becomes blocked, defending player discards a card.

Warehouse Tabby

Whenever an enchantment you control is put into a graveyard from the battlefield, create a 1/1 black Rat creature token with "This token can't block."
{1}{B}: This creature gains deathtouch until end of turn.

Mardu Skullhunter

This creature enters tapped.
Raid — When this creature enters, if you attacked this turn, target opponent discards a card.

Fell Specter

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

Strands of Undeath

Enchant creature
When this Aura enters, target player discards two cards.
{B}: Regenerate enchanted creature.

Poison the Waters

Choose one —
• All creatures get -1/-1 until end of turn.
• Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Prickle Faeries

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

Invasion of Eldraine

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, target opponent discards two cards.

Invasion of Eldraine // Prickle Faeries

Mindstab Thrull

Whenever this creature attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Shadow Alley Denizen

Whenever another black creature you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Swamp

March of the Returned

Return up to two target creature cards from your graveyard to your hand.

Dark Banishing

Destroy target nonblack creature. It can't be regenerated.

Death's Approach

Enchant creature
Enchanted creature gets -X/-X, where X is the number of creature cards in its controller's graveyard.

Case of the Gorgon's Kiss

When this Case enters, destroy up to one target creature that was dealt damage this turn.
To solve — Three or more creature cards were put into graveyards from anywhere this turn. (If unsolved, solve at the beginning of your end step.)
Solved — This Case is a 4/4 Gorgon creature with deathtouch and lifelink in addition to its other types.

Mind Rot

Arcane Signet

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

Larceny

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

Morbid Plunder

Agent Venom

Flash
Menace
Whenever another nontoken creature you control dies, you draw a card and lose 1 life.

Cruel Grimnarch

Deathtouch
When this creature enters, each opponent discards a card. For each opponent who can't, you gain 4 life.

Mindstab

Target player discards three cards.
Suspend 4—{B} (Rather than cast this card from your hand, you may pay {B} 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.)

Hoarding Broodlord

Convoke
Flying
When this creature enters, search your library for a card, exile it face down, then shuffle. For as long as that card remains exiled, you may play it.
Spells you cast from exile have convoke.

Megrim

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

Ripclaw Wrangler

When this Vehicle enters, each opponent discards a card.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Scandalmonger

{2}: Target player discards a card. Any player may activate this ability but only as a sorcery.

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Macabre Waltz

Return up to two target creature cards from your graveyard to your hand, then discard a card.

Culling the Weak

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

Mind Ravel

Target player discards a card.
Draw a card at the beginning of the next turn's upkeep.

Soulless Jailer

Permanent cards in graveyards can't enter the battlefield.
Players can't cast noncreature spells from graveyards or exile.

Fanatic of the Harrowing

When this creature enters, each player discards a card. If you discarded a card this way, draw a card.

Quest for the Nihil Stone

Whenever an opponent discards a card, you may put a quest counter on this enchantment.
At the beginning of each opponent's upkeep, if that player has no cards in hand and this enchantment has two or more quest counters on it, you may have that player lose 5 life.

Malboro

Bad Breath — When this creature enters, each opponent discards a card, loses 2 life, and exiles the top three cards of their library.
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Corrupt Court Official

When this creature enters, target opponent discards a card.

Haunt of the Dead Marshes

When this creature enters, scry 1.
{2}{B}: Return this card from your graveyard to the battlefield tapped. Activate only if you control a legendary creature.

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+.)
STATION 1+
Whenever an opponent discards a card, they lose 3 life.
STATION 8+
Flying, deathtouch
Whenever this Spacecraft attacks, each opponent discards a card. Each opponent who can't loses 3 life.

Elderfang Disciple

When this creature enters, each opponent discards a card.

Emperor of Bones

At the beginning of combat on your turn, exile up to one target card from a graveyard.
{1}{B}: Adapt 2.
Whenever one or more +1/+1 counters are put on this creature, put a creature card exiled with this creature onto the battlefield under your control with a finality counter on it. It gains haste. Sacrifice it at the beginning of the next end step.

Necrogen Spellbomb

{B}, Sacrifice this artifact: Target player discards a card.
{1}, Sacrifice this artifact: Draw a card.

Dark Ritual

Dementia Bat

Flying
{4}{B}, Sacrifice this creature: Target player discards two cards.

Hopeless Nightmare

When this enchantment enters, each opponent discards a card and loses 2 life.
When this enchantment is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice this enchantment.

Chilling Apparition

{B}: Regenerate this creature.
Whenever this creature deals combat damage to a player, that player discards a card.