Remove?

Garna, the Bloodflame

Flash
When Garna enters, return to your hand all creature cards in your graveyard that were put there from anywhere this turn.
Other creatures you control have haste.

Archfiend of Ifnir

Flying
Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sycorax Commander

First strike, haste
Sanctified Rules of Combat — When this creature enters, each opponent faces a villainous choice — That opponent discards all the cards in their hand, then draws that many cards minus one, or this creature deals damage to that player equal to the number of cards in their hand.

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.

Winter, Misanthropic Guide

Ward {2}
At the beginning of your upkeep, each player draws two cards.
Delirium — As long as there are four or more card types among cards in your graveyard, each opponent's maximum hand size is equal to seven minus the number of those card types.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Welcome the Dead

Draw two cards, then discard a card and you lose 2 life. Create X tapped 2/2 black Zombie Druid creature tokens, where X is the number of cards that were put into your graveyard from your hand or library this turn.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Oppression

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

Webstrike Elite

Reach
Cycling {X}{G}{G} ({X}{G}{G}, Discard this card: Draw a card.)
When you cycle this card, destroy up to one target artifact or enchantment with mana value X.

Geth's Grimoire

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

Add?

Grist, the Hunger Tide

As long as Grist isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

Change of Fortune

Discard your hand, then draw a card for each card you've discarded this turn.

Arcane Signet

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

Soul of Windgrace

Whenever Soul of Windgrace enters or attacks, you may put a land card from a graveyard onto the battlefield tapped under your control.
{G}, Discard a land card: You gain 3 life.
{1}{R}, Discard a land card: Draw a card.
{2}{B}, Discard a land card: Soul of Windgrace gains indestructible until end of turn. Tap it.

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{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.)

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Necrogen Mists

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

Abandoned Sarcophagus

You may cast spells that have a cycling ability from your graveyard.
If a card that has a cycling ability would be put into your graveyard from anywhere and it wasn't cycled, exile it instead.

Dying to Serve

Whenever you discard one or more cards, create a tapped 2/2 black Zombie creature token. This ability triggers only once each turn.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Shadowblood Ridge

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

Rampaging War Mammoth

Trample
Cycling {X}{2}{R} ({X}{2}{R}, Discard this card: Draw a card.)
When you cycle this card, destroy up to X target artifacts.

Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice this artifact: Return all cards exiled with this artifact to their owner's hand.

Demonic Counsel

Search your library for a Demon card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for any card, put it into your hand, then shuffle.

Faith of the Devoted

Whenever you cycle or discard a card, you may pay {1}. If you do, each opponent loses 2 life and you gain 2 life.

Woodland Cemetery

This land enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Asmoranomardicadaistinaculdacar

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell.
When Asmoranomardicadaistinaculdacar enters, you may search your library for a card named The Underworld Cookbook, reveal it, put it into your hand, then shuffle.
Sacrifice two Foods: Target creature deals 6 damage to itself.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Argentum Masticore

First strike, protection from multicolored
At the beginning of your upkeep, sacrifice this creature unless you discard a card. When you discard a card this way, destroy target nonland permanent an opponent controls with mana value less than or equal to the mana value of the discarded card.

Deluge of Doom

All creatures get -X/-X until end of turn, where X is the number of card types among cards in your graveyard.

Snort

Each player may discard their hand and draw five cards. Then Snort deals 5 damage to each opponent who discarded their hand this way.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

Nath of the Gilt-Leaf

At the beginning of your upkeep, you may have target opponent discard a card at random.
Whenever an opponent discards a card, you may create a 1/1 green Elf Warrior creature token.

Squirming Emergence

Fathomless descent — Return to the battlefield target nonland permanent card in your graveyard with mana value less than or equal to the number of permanent cards in your graveyard.

Unpredictable Cyclone

If a cycling ability of another nonland card would cause you to draw a card, instead exile cards from the top of your library until you exile a card that shares a card type with the cycled card. You may cast that card without paying its mana cost. Then put the exiled cards that weren't cast this way on the bottom of your library in a random order.
Cycling {2} ({2}, Discard this card: Draw a card.)

Desert of the Glorified

This land enters tapped.
{T}: Add {B}.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

Squee, Goblin Nabob

At the beginning of your upkeep, you may return this card from your graveyard to your hand.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Sol Ring

Deathrite Shaman

{T}: Exile target land card from a graveyard. Add one mana of any color.
{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.
{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Tranquil Thicket

This land enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Swamp

Kyren Flamewright

{2}{R}, {T}, Discard a card: Create two 1/1 blue and red Elemental creature tokens. Creatures you control get +1/+0 and gain haste until end of turn.

Invasion of Mercadia

(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, you may discard a card. If you do, draw two cards.

Invasion of Mercadia // Kyren Flamewright

Haywire Mite

When this creature dies, you gain 2 life.
{G}, Sacrifice this creature: Exile target noncreature artifact or noncreature enchantment.

Slippery Karst

This land enters tapped.
{T}: Add {G}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Beneath the Sands

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, all creatures get -2/-2 until end of turn.

Twilight Mire

{T}: Add {C}.
{B/G}, {T}: Add {B}{B}, {B}{G}, or {G}{G}.

Smoldering Crater

This land enters tapped.
{T}: Add {R}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Fluctuator

Cycling abilities you activate cost {2} less to activate.

Wilt

Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice this enchantment.

Bone Miser

Whenever you discard a creature card, create a 2/2 black Zombie creature token.
Whenever you discard a land card, add {B}{B}.
Whenever you discard a noncreature, nonland card, draw a card.

Monument to Endurance

Whenever you discard a card, choose one that hasn't been chosen this turn —
• Draw a card.
• Create a Treasure token.
• Each opponent loses 3 life.

Magmakin Artillerist

Whenever you discard one or more cards, this creature deals that much damage to each opponent.
Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)
When you cycle this card, it deals 1 damage to each opponent.

Grimoire of the Dead

{1}, {T}, Discard a card: Put a study counter on Grimoire of the Dead.
{T}, Remove three study counters from Grimoire of the Dead and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.

Lightning Rift

Whenever a player cycles a card, you may pay {1}. If you do, this enchantment deals 2 damage to any target.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Hollow Marauder

This spell costs {1} less to cast for each creature card in your graveyard.
Flying
When this creature enters, any number of target opponents each discard a card. For each of those opponents who didn't discard a card with mana value 4 or greater, draw a card.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice this creature: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

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.

Don't Have

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Hostile Investigator

When this creature enters, target opponent discards a card.
Whenever one or more players discard one or more cards, investigate. This ability triggers only once each turn. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw 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.

Syphon Mind

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

Surly Badgersaur

Whenever you discard a creature card, put a +1/+1 counter on this creature.
Whenever you discard a land card, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you discard a noncreature, nonland card, this creature fights up to one target creature you don't control.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Sheltered Thicket

({T}: Add {R} or {G}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Neheb, the Worthy

First strike
Other Minotaurs you control have first strike.
As long as you have one or fewer cards in hand, Minotaurs you control get +2/+0.
Whenever Neheb deals combat damage to a player, each player discards a card.

Cryptcaller Chariot

Menace
Whenever you discard one or more cards, create that many tapped 2/2 black Zombie creature tokens.
Crew 2

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.

Temple of the Dead

(Transforms from Aclazotz, Deepest Betrayal.)
{T}: Add {B}.
{2}{B}, {T}: Transform this land. Activate only if a player has one or fewer cards in hand and only as a sorcery.

Aclazotz, Deepest Betrayal

Flying, lifelink
Whenever Aclazotz attacks, each opponent discards a card. For each opponent who can't, you draw a card.
Whenever an opponent discards a land card, create a 1/1 black Bat creature token with flying.
When Aclazotz dies, return it to the battlefield tapped and transformed under its owner's control.

Aclazotz, Deepest Betrayal // Temple of the Dead

Fellwar Stone

Drannith Stinger

Whenever you cycle another card, this creature deals 1 damage to each opponent.
Cycling {1} ({1}, Discard this card: Draw a card.)

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: 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.

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.

Sire of Insanity

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

Brallin, Skyshark Rider

Partner with Shabraz, the Skyshark (When this creature enters, target player may put Shabraz into their hand from their library, then shuffle.)
Whenever you discard a card, put a +1/+1 counter on Brallin and it deals 1 damage to each opponent.
{R}: Target Shark gains trample until end of turn.

Mountain

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.

Reforge the Soul

Each player discards their hand, then draws seven cards.
Miracle {1}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Anje Falkenrath

Haste
{T}, Discard a card: Draw a card.
Whenever you discard a card, if it has madness, untap Anje Falkenrath.

Festering Thicket

({T}: Add {B} or {G}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Inti, Seneschal of the Sun

Whenever you attack, you may discard a card. When you do, put a +1/+1 counter on target attacking creature. It gains trample until end of turn.
Whenever you discard one or more cards, exile the top card of your library. You may play that card until your next end step.

Rakdos Signet

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.

Forest

Pyre of the World Tree

Discard a land card: This enchantment deals 2 damage to any target.
Whenever you discard a land card, exile the top card of your library. You may play that card this turn.

Invasion of Kaldheim

(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, exile all cards from your hand, then draw that many cards. Until the end of your next turn, you may play cards exiled this way.