+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.

Choose one — • Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard. • Counter target activated or triggered ability.

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may shuffle up to four target cards from your graveyard into your library.

Counter target creature or planeswalker spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. Scry 1.

Menace When Atris, Oracle of Half-Truths enters the battlefield, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Devoid (This card has no color.) Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.) Benthic Infiltrator can't be blocked.

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 that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Whenever one or more cards are put into your graveyard from your library, Devourer of Memory gets +1/+1 until end of turn and can't be blocked this turn. {1}{U}{B}: Mill a card.

Menace Whenever Elder Brain attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Devoid (This card has no color.) Deathtouch Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.) {3}{U}{B}: Draw a card. Each opponent exiles the top card of their library.

Grimdancer enters the battlefield with your choice of two different counters on it from among menace, deathtouch, and lifelink.

Devoid (This card has no color.) Flying Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)

Flying Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Flying Whenever Nightveil Specter deals combat damage to a player, that player exiles the top card of their library. You may play lands and cast spells from among cards exiled with Nightveil Specter.

Devoid (This card has no color.) Whenever a land enters the battlefield under an opponent's control, that player exiles the top two cards of their library and you draw two cards.

Flying Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast it.

At the beginning of each end step, put a slime counter on each creature you don't control. Creatures you don't control get -1/-1 for each slime counter on them. Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token. {U}{B}, Sacrifice a Slug: Draw a card.

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

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.

+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.

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.

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may look at and play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell. Flashback {1}{U}{B}

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

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

({T}: Add {U} or {B}.) Contaminated Aquifer enters the battlefield tapped.

Dimir Aqueduct enters the battlefield tapped. When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand. {T}: Add {U}{B}.

Dimir Guildgate enters the battlefield tapped. {T}: Add {U} or {B}.

Dismal Backwater enters the battlefield tapped. When Dismal Backwater enters the battlefield, you gain 1 life. {T}: Add {U} or {B}.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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

{T}: Add {C}. {T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Whenever you cast a planeswalker spell, you gain 1 life. {T}: Add {C}. {1}, {T}: Add two mana of different colors. Spend this mana only to cast planeswalker spells.

({T}: Add {U}.)

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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

{T}: Add {C}. {1}{U}{B}, {T}: Target player mills three cards.

Submerged Boneyard enters the battlefield tapped. {T}: Add {U} or {B}.

({T}: Add {B}.)

The Surgical Bay enters the battlefield tapped. {T}: Add {U}. {1}{U}, {T}, Sacrifice The Surgical Bay: Draw a card.

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

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

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

At the beginning of your upkeep, repeat the following process for each opponent in turn order. Reveal the top card of your library. That player may pay life equal to that card's mana value. If they do, exile that card. Otherwise, put it into your hand.

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Exile target creature or planeswalker. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Choose odd or even. Exile each creature with mana value of the chosen quality. (Zero is even.)

Exile target creature or planeswalker. You gain life equal to the number of counters on it.

Exile target creature. Put two loyalty counters on a planeswalker you control.