Ancient Cellarspawn

Each spell you cast that's a Demon, Horror, or Nightmare costs {1} less to cast.
Whenever you cast a spell, if the amount of mana spent to cast it was less than its mana value, target opponent loses life equal to the difference.

Peculiar Lighthouse

This land enters tapped unless a player has 13 or less life.
{T}: Add {U} or {R}.

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.

Cadaver Lab

When you unlock this door, return target creature card from your graveyard to your hand.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Defiled Crypt

Whenever one or more cards leave your graveyard, create a 2/2 black Horror enchantment creature token. This ability triggers only once each turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Defiled Crypt // Cadaver Lab

Valgavoth's Lair

Hexproof
This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Warped Space

Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast from exile.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer

At the beginning of your upkeep, exile the top card of your library. You may play it this turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Charred Foyer // Warped Space

Marina Vendrell

When Marina Vendrell enters, reveal the top seven cards of your library. Put all enchantment cards from among them into your hand and the rest on the bottom of your library in a random order.
{T}: Lock or unlock a door of target Room you control. Activate only as a sorcery.

Fear of Exposure

As an additional cost to cast this spell, tap two untapped creatures and/or lands you control.
Trample

Forest

Mountain

Blazemire Verge

{T}: Add {B}.
{T}: Add {R}. Activate only if you control a Swamp or a Mountain.

Razortrap Gorge

This land enters tapped unless a player has 13 or less life.
{T}: Add {B} or {R}.

Ritual Chamber

When you unlock this door, create a 6/6 black Demon creature token with flying.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life and you gain 2 life. Otherwise, you lose 2 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex // Ritual Chamber

Dusty Parlor

Whenever you cast an enchantment spell, put a number of +1/+1 counters equal to that spell's mana value on up to one target creature.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Secret Arcade

Nonland permanents you control and permanent spells you control are enchantments in addition to their other types.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Secret Arcade // Dusty Parlor

Fear of Immobility

When this creature enters, tap up to one target creature. If an opponent controls that creature, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Creeping Peeper

{T}: Add {U}. Spend this mana only to cast an enchantment spell, unlock a door, or turn a permanent face up.

Lecture Hall

Other permanents you control have hexproof.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Restricted Office

When you unlock this door, destroy all creatures with power 3 or greater.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Restricted Office // Lecture Hall

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Ghostly Keybearer

Flying
Whenever this creature deals combat damage to a player, unlock a locked door of up to one target Room you control.

Valgavoth, Harrower of Souls

Flying
Ward—Pay 2 life.
Whenever an opponent loses life for the first time during each of their turns, put a +1/+1 counter on Valgavoth and draw a card.

Arcane Signet

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

Floodfarm Verge

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

Murky Sewer

This land enters tapped unless a player has 13 or less life.
{T}: Add {U} or {B}.

The World Tree

This land enters tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice this land: Search your library for any number of God cards, put them onto the battlefield, then shuffle.

Fear of Falling

Flying
Whenever this creature attacks, target creature defending player controls gets -2/-0 and loses flying until your next turn.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Weight Room

When you unlock this door, manifest dread, then put three +1/+1 counters on that creature.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Moldering Gym

When you unlock this door, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Moldering Gym // Weight Room

Fear of Burning Alive

When this creature enters, it deals 4 damage to each opponent.
Delirium — Whenever a source you control deals noncombat damage to an opponent, if there are four or more card types among cards in your graveyard, this creature deals that amount of damage to target creature that player controls.

Overlord of the Floodpits

Impending 4—{1}{U}{U} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Flying
Whenever this permanent enters or attacks, draw two cards, then discard a card.

Fear of Being Hunted

Haste
This creature must be blocked if able.

Elegant Rotunda

When you unlock this door, put a +1/+1 counter on each of up to two target creatures.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Grand Entryway

When you unlock this door, create a 1/1 white Glimmer enchantment creature token.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Grand Entryway // Elegant Rotunda

Drowned Diner

When you unlock this door, draw three cards, then discard a card.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Meat Locker

When you unlock this door, tap up to one target creature and put two stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Meat Locker // Drowned Diner

Plains

Fear of Abduction

As an additional cost to cast this spell, exile a creature you control.
Flying
When this creature enters, exile target creature an opponent controls.
When this creature leaves the battlefield, put each card exiled with it into its owner's hand.

Steaming Sauna

You have no maximum hand size.
At the beginning of your end step, draw a card.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Roaring Furnace

When you unlock this door, this Room deals damage equal to the number of cards in your hand to target creature an opponent controls.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Roaring Furnace // Steaming Sauna

Overlord of the Balemurk

Impending 5—{1}{B} (If you cast this spell for its impending cost, it enters with five time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, mill four cards, then you may return a non-Avatar creature card or a planeswalker card from your graveyard to your hand.

Strangled Cemetery

This land enters tapped unless a player has 13 or less life.
{T}: Add {B} or {G}.

Thornspire Verge

{T}: Add {R}.
{T}: Add {G}. Activate only if you control a Mountain or a Forest.

Island

Rampant Growth

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

Fear of the Dark

Whenever this creature attacks, if defending player controls no Glimmer creatures, it gains menace and deathtouch until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Lakeside Shack

This land enters tapped unless a player has 13 or less life.
{T}: Add {G} or {U}.

Porcelain Gallery

Creatures you control have base power and toughness each equal to the number of creatures you control.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dollmaker's Shop

Whenever one or more non-Toy creatures you control attack a player, create a 1/1 white Toy artifact creature token.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dollmaker's Shop // Porcelain Gallery

Vindicate

Forgotten Cellar

When you unlock this door, you may cast spells from your graveyard this turn, and if a card would be put into your graveyard from anywhere this turn, exile it instead.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Walk-In Closet

You may play lands from your graveyard.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Walk-In Closet // Forgotten Cellar

Fear of Missing Out

When this creature enters, discard a card, then draw a card.
Delirium — Whenever this creature attacks for the first time each turn, if there are four or more card types among cards in your graveyard, untap target creature. After this phase, there is an additional combat phase.

Dim Oubliette

When you unlock this door, mill three cards, then return a creature card from your graveyard to the battlefield.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Polluted Cistern

Whenever one or more cards are put into your graveyard from your library, each opponent loses 1 life for each card type among those cards.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Polluted Cistern // Dim Oubliette

Staff Room

Whenever a creature you control deals combat damage to a player, turn that creature face up or put a +1/+1 counter on it.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Experimental Lab

When you unlock this door, manifest dread, then put two +1/+1 counters and a trample counter on that creature.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Experimental Lab // Staff Room

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Defaced Gallery

Whenever you attack, attacking creatures you control get +1/+0 until end of turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Painter's Studio

When you unlock this door, exile the top two cards of your library. You may play them until the end of your next turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Painter's Studio // Defaced Gallery

Overlord of the Hauntwoods

Impending 4—{1}{G}{G} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, create a tapped colorless land token named Everywhere that is every basic land type.

Sol Ring

Enchantress's Presence

Whenever you cast an enchantment spell, draw a card.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Etched Cornfield

This land enters tapped unless a player has 13 or less life.
{T}: Add {G} or {W}.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Fear of Impostors

Flash
When this creature 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.)

Fear of Failed Tests

Whenever this creature deals combat damage to a player, draw that many cards.

Fear of Infinity

Flying, lifelink
This creature can't block.
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, you may return this card from your graveyard to your hand.

Fear of Sleep Paralysis

Flying
Eerie — Whenever this creature or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Farseek

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

The Master of Keys

Flying
When The Master of Keys enters, put X +1/+1 counters on it and mill twice X cards.
Each enchantment 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.)

Neglected Manor

This land enters tapped unless a player has 13 or less life.
{T}: Add {W} or {B}.

Abandoned Campground

This land enters tapped unless a player has 13 or less life.
{T}: Add {W} or {U}.

Fear of Isolation

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

Keys to the House

{1}, {T}, Sacrifice this artifact: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{3}, {T}, Sacrifice this artifact: Lock or unlock a door of target Room you control. Activate only as a sorcery.

Overlord of the Boilerbilges

Impending 4—{2}{R}{R} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever this permanent enters or attacks, it deals 4 damage to any target.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Bleeding Woods

This land enters tapped unless a player has 13 or less life.
{T}: Add {R} or {G}.

Swamp

Hushwood Verge

{T}: Add {G}.
{T}: Add {W}. Activate only if you control a Forest or a Plains.

Entity Tracker

Flash
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, draw a card.

Fear of Lost Teeth

When this creature dies, it deals 1 damage to any target and you gain 1 life.

Unwanted Remake

Destroy target creature. 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.)

Fear of Surveillance

Vigilance
Whenever this creature attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Shattered Yard

At the beginning of your end step, this Room deals 1 damage to each opponent.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Glassworks

When you unlock this door, this Room deals 4 damage to target creature an opponent controls.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Glassworks // Shattered Yard

Gloomlake Verge

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

Slimy Aquarium

When you unlock this door, manifest dread, then put a +1/+1 counter on that creature.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Underwater Tunnel

When you unlock this door, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Underwater Tunnel // Slimy Aquarium

Tunnel of Hate

Whenever you attack, target attacking creature gains double strike until end of turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)