Fear of Isolation

As an additional cost to cast this spell, return a permanent you control to its owner's hand.
Flying

Defiler of Flesh

Menace
As an additional cost to cast black permanent spells, you may pay 2 life. Those spells cost {B} less to cast if you paid life this way. This effect reduces only the amount of black mana you pay.
Whenever you cast a black permanent spell, target creature you control gets +1/+1 and gains menace until end of turn.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Negate

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Crown of Ascension

Enchant creature
Enchanted creature has flying.
Sacrifice Crown of Ascension: Enchanted creature and other creatures that share a creature type with it gain flying until end of turn.

Witch's Cottage

({T}: Add {B}.)
Witch's Cottage enters tapped unless you control three or more other Swamps.
When Witch's Cottage enters untapped, you may put target creature card from your graveyard on top of your library.

Ashiok, Nightmare Weaver

+2: Exile the top three cards of target opponent's library.
−X: Put a creature card with mana value X exiled with Ashiok, Nightmare Weaver onto the battlefield under your control. That creature is a Nightmare in addition to its other types.
−10: Exile all cards from all opponents' hands and graveyards.

Infernal Idol

{T}: Add {B}.
{1}{B}{B}, {T}, Sacrifice Infernal Idol: You draw two cards and you lose 2 life.

Krydle of Baldur's Gate

Whenever Krydle of Baldur's Gate deals combat damage to a player, that player loses 1 life and mills a card, then you gain 1 life and scry 1.
Whenever you attack, you may pay {2}. If you do, target creature can't be blocked this turn.

Sands of Delirium

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Swamp

Soul-Guide Lantern

When this artifact enters, exile target card from a graveyard.
{T}, Sacrifice this artifact: Exile each opponent's graveyard.
{1}, {T}, Sacrifice this artifact: Draw a card.

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Diabolic Tutor

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

Clammy Prowler

Whenever Clammy Prowler attacks, another target attacking creature can't be blocked this turn.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Arvinox, the Mind Flail

Arvinox, the Mind Flail isn't a creature unless you control three or more permanents you don't own.
At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Ichorid

Haste
At the beginning of the end step, sacrifice Ichorid.
At the beginning of your upkeep, if Ichorid is in your graveyard, you may exile a black creature card other than Ichorid from your graveyard. If you do, return Ichorid to the battlefield.

Fear of Impostors

Flash
When Fear of Impostors enters, counter target spell. Its controller manifests dread. (That player looks at the top two cards of their library, then puts one onto the battlefield face down as a 2/2 creature and the other into their graveyard. If it's a creature card, it can be turned face up any time for its mana cost.)

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Terisian Mindbreaker

Whenever Terisian Mindbreaker attacks, defending player mills half their library, rounded up.
Unearth {1}{U}{U}{U} ({1}{U}{U}{U}: 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.)

Darkwater Catacombs

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Curse of Unbinding

Enchant player
At the beginning of enchanted player's upkeep, that player reveals cards from the top of their library until they reveal a creature card. Put that card onto the battlefield under your control. That player puts the rest of the revealed cards into their graveyard.

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

Forgotten Creation

Skulk (This creature can't be blocked by creatures with greater power.)
At the beginning of your upkeep, you may discard all the cards in your hand. If you do, draw that many cards.

Dreams of Steel and Oil

Target opponent reveals their hand. You choose an artifact or creature card from it, then choose an artifact or creature card from their graveyard. Exile the chosen cards.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Rogue's Passage

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

Sol Ring

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Murder

Sky Diamond

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Fleshwrither

Transfigure {1}{B}{B} ({1}{B}{B}, Sacrifice this creature: Search your library for a creature card with the same mana value as this creature, put that card onto the battlefield, then shuffle. Transfigure only as a sorcery.)

Command Tower

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

Stonespeaker Crystal

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Stonespeaker Crystal: Exile any number of target players' graveyards. Draw a card.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Fraying Sanity

Enchant player
At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn.

Ravenous Trap

If an opponent had three or more cards put into their graveyard from anywhere this turn, you may pay {0} rather than pay this spell's mana cost.
Exile target player's graveyard.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Cunning Rhetoric

Whenever an opponent attacks you and/or one or more planeswalkers you control, exile the top card of that player's library. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast it.

Umbris, Fear Manifest

Umbris, Fear Manifest gets +1/+1 for each card your opponents own in exile.
Whenever Umbris or another Nightmare or Horror you control enters, target opponent exiles cards from the top of their library until they exile a land card.

Mesmeric Fiend

When Mesmeric Fiend enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When Mesmeric Fiend leaves the battlefield, return the exiled card to its owner's hand.

Agonizing Remorse

Target opponent reveals their hand. You choose a nonland card from it or a card from their graveyard. Exile that card. You lose 1 life.

Zellix, Sanity Flayer

Hive Mind — Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.
{1}, {T}: Target player mills three cards.
Choose a Background (You can have a Background as a second commander.)

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Fear of Failed Tests

Whenever Fear of Failed Tests deals combat damage to a player, draw that many cards.

Captain N'ghathrod

Horrors you control have menace.
Whenever a Horror you control deals combat damage to a player, that player mills that many cards.
At the beginning of your end step, choose target artifact or creature card in an opponent's graveyard that was put there from their library this turn. Put it onto the battlefield under your control.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Awoken Horror

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

Thing in the Ice

Defender
Thing in the Ice enters with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.

Thing in the Ice // Awoken Horror

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Tasha's Hideous Laughter

Each opponent exiles cards from the top of their library until that player has exiled cards with total mana value 20 or more.

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Gloomlake Verge

{T}: Add {U}.
{T}: Add {B}. Activate only if you control an Island or a Swamp.

Go for the Throat

Arcane Signet

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Traumatize

Target player mills half their library, rounded down.

Counterspell

Ashiok, Nightmare Muse

+1: Create a 2/3 blue and black Nightmare creature token with "Whenever this creature attacks or blocks, each opponent exiles the top two cards of their library."
−3: Return target nonland permanent to its owner's hand, then that player exiles a card from their hand.
−7: You may cast up to three spells from among face-up cards your opponents own from exile without paying their mana costs.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Phyrexian Revoker

As Phyrexian Revoker enters, choose a nonland card name.
Activated abilities of sources with the chosen name can't be activated.

Fell

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Just the Wind

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

Island

Drown in Dreams

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Target player draws X cards.
• Target player mills twice X cards.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Abyssal Gorestalker

When Abyssal Gorestalker enters, each player sacrifices two creatures of their choice.

Silent Hallcreeper

Silent Hallcreeper can't be blocked.
Whenever Silent Hallcreeper deals combat damage to a player, choose one that hasn't been chosen —
• Put two +1/+1 counters on Silent Hallcreeper.
• Draw a card.
• Silent Hallcreeper becomes a copy of another target creature you control.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.