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 Overlord of the Floodpits enters or attacks, draw two cards, then discard a card.

Glimmerburst

Draw two cards. Create a 1/1 white Glimmer enchantment creature token.

Irreverent Gremlin

Menace (This creature can't be blocked except by two or more creatures.)
Whenever another creature you control with power 2 or less enters, you may discard a card. If you do, draw a card. Do this only once each turn.

Norin, Swift Survivalist

Norin, Swift Survivalist can't block.
Whenever a creature you control becomes blocked, you may exile it. You may play that card from exile this turn.

Final Vengeance

As an additional cost to cast this spell, sacrifice a creature or enchantment.
Exile target creature.

Frantic Strength

Flash
Enchant creature
Enchanted creature gets +2/+2 and has trample.

Popular Egotist

{1}{B}, Sacrifice another creature or enchantment: Popular Egotist gains indestructible until end of turn. Tap it. (Damage and effects that say "destroy" don't destroy it.)
Whenever you sacrifice a permanent, target opponent loses 1 life and you gain 1 life.

Grasping Longneck

Reach
When Grasping Longneck dies, you gain 2 life.

Twist Reality

Choose one —
• Counter target spell.
• Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Seized from Slumber

This spell costs {3} less to cast if it targets a tapped creature.
Destroy target creature.

Tunnel Surveyor

When Tunnel Surveyor enters, create a 1/1 white Glimmer enchantment creature token.

Living Phone

When Living Phone dies, look at the top five cards of your library. You may reveal a creature card with power 2 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Gremlin Tamer

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, create a 1/1 red Gremlin creature token.

Exorcise

Exile target artifact, enchantment, or creature with power 4 or greater.

Fear of Lost Teeth

When Fear of Lost Teeth dies, it deals 1 damage to any target and you gain 1 life.

Rampaging Soulrager

Rampaging Soulrager gets +3/+0 as long as there are two or more unlocked doors among Rooms you control.

Rootwise Survivor

Haste
Survival — At the beginning of your second main phase, if Rootwise Survivor is tapped, put three +1/+1 counters on up to one target land you control. That land becomes a 0/0 Elemental creature in addition to its other types. It gains haste until your next turn.

Widow's Walk

(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.)
Whenever a creature you control attacks alone, it gets +1/+0 and gains deathtouch until end of turn.

Derelict Attic

(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.)
When you unlock this door, you draw two cards and you lose 2 life.

Derelict Attic // Widow's Walk

Split Up

Choose one —
• Destroy all tapped creatures.
• Destroy all untapped creatures.

Found Footage

You may look at face-down creatures your opponents control any time.
{2}, Sacrifice Found Footage: Surveil 2, then draw a card. (To 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.)

Jump Scare

Until end of turn, target creature gets +2/+2, gains flying, and becomes a Horror enchantment creature in addition to its other types.

Clockwork Percussionist

Haste
When Clockwork Percussionist dies, exile the top card of your library. You may play it until the end of your next turn.

Diversion Specialist

Menace (This creature can't be blocked except by two or more creatures.)
{1}, Sacrifice another creature or enchantment: Exile the top card of your library. You may play it this turn.

Say Its Name

Mill three cards. Then you may return a creature or land card from your graveyard to your hand.
Exile this card and two other cards named Say Its Name from your graveyard: Search your graveyard, hand, and/or library for a card named Altanak, the Thrice-Called and put it onto the battlefield. If you search your library this way, shuffle. Activate only as a sorcery.

Hardened Escort

Whenever Hardened Escort attacks, another target creature you control gets +1/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Lakeside Shack

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

Weight Room

(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.)
When you unlock this door, manifest dread, then put three +1/+1 counters on that creature.

Moldering Gym

(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.)
When you unlock this door, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Moldering Gym // Weight Room

Entity Tracker

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

Wary Watchdog

When Wary Watchdog enters or dies, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Floodpits Drowner

Flash
Vigilance
When Floodpits Drowner enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle Floodpits Drowner and target creature with a stun counter on it into their owners' libraries.

Get Out

Choose one —
• Counter target creature or enchantment spell.
• Return one or two target creatures and/or enchantments you own to your hand.

Killer's Mask

When Killer's Mask enters, manifest dread, then attach Killer's Mask to that creature. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
Equipped creature has menace.
Equip {2}

Fear of the Dark

Whenever Fear of the Dark 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.)

Possessed Goat

{3}, Discard a card: Put three +1/+1 counters on Possessed Goat and it becomes a black Demon in addition to its other colors and types. Activate only once.

Piranha Fly

Bashful Beastie

When Bashful Beastie dies, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Vile Mutilator

As an additional cost to cast this spell, sacrifice a creature or enchantment.
Flying, trample
When Vile Mutilator enters, each opponent sacrifices a nontoken enchantment, then sacrifices a nontoken creature.

Scrabbling Skullcrab

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Stalked Researcher

Defender
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, Stalked Researcher can attack this turn as though it didn't have defender.

Wickerfolk Thresher

Delirium — Whenever Wickerfolk Thresher attacks, if there are four or more card types among cards in your graveyard, look at the top card of your library. If it's a land card, you may put it onto the battlefield. If you don't put the card onto the battlefield, put it into your hand.

Hospital Room

(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.)
Whenever you attack, put a +1/+1 counter on target attacking creature.

Surgical Suite

(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.)
When you unlock this door, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Surgical Suite // Hospital Room

Rip, Spawn Hunter

Survival — At the beginning of your second main phase, if Rip, Spawn Hunter is tapped, reveal the top X cards of your library, where X is its power. Put any number of creature and/or Vehicle cards with different powers from among them into your hand. Put the rest on the bottom of your library in a random order.

Trial of Agony

Choose two target creatures controlled by the same opponent. That player chooses one of those creatures. Trial of Agony deals 5 damage to that creature, and the other can't block this turn.

Malevolent Chandelier

Flying
{2}: Put target card from a graveyard on the bottom of its owner's library. Activate only as a sorcery.

Ripchain Razorkin

Reach
{2}{R}, Sacrifice a land: Draw a card.

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Awakening Hall

(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.)
When you unlock this door, return all creature cards from your graveyard to the battlefield.

Funeral Room

(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.)
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Funeral Room // Awakening Hall

Baseball Bat

When Baseball Bat enters, attach it to target creature you control.
Equipped creature gets +1/+1.
Whenever equipped creature attacks, tap up to one target creature.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Scorching Dragonfire

Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Glimmer Seeker

Survival — At the beginning of your second main phase, if Glimmer Seeker is tapped, draw a card if you control a Glimmer creature. If you don't control a Glimmer creature, create a 1/1 white Glimmer enchantment creature token.

The Swarmweaver

When The Swarmweaver enters, create two 1/1 black and green Insect creature tokens with flying.
Delirium — As long as there are four or more card types among cards in your graveyard, Insects and Spiders you control get +1/+1 and have deathtouch.

Under the Skin

Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
You may return a permanent card from your graveyard to your hand.

Patchwork Beastie

Delirium — Patchwork Beastie can't attack or block unless there are four or more card types among cards in your graveyard.
At the beginning of your upkeep, you may mill a card. (You may put the top card of your library into your 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.

Cadaver Lab

(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.)
When you unlock this door, return target creature card from your graveyard to your hand.

Defiled Crypt

(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.)
Whenever one or more cards leave your graveyard, create a 2/2 black Horror enchantment creature token. This ability triggers only once each turn.

Defiled Crypt // Cadaver Lab

Horrid Vigor

Target creature gains deathtouch and indestructible until end of turn.

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.)

Vanish from Sight

Target nonland permanent's owner puts it on the top or bottom of their library. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Growing Dread

Flash
When Growing Dread enters, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
Whenever you turn a permanent face up, put a +1/+1 counter on it.

Acrobatic Cheerleader

Survival — At the beginning of your second main phase, if Acrobatic Cheerleader is tapped, put a flying counter on it. This ability triggers only once.

Sheltered by Ghosts

Enchant creature you control
When Sheltered by Ghosts enters, exile target nonland permanent an opponent controls until Sheltered by Ghosts leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Terramorphic Expanse

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

Sawblade Skinripper

Menace
{2}, Sacrifice another creature or enchantment: Put a +1/+1 counter on Sawblade Skinripper.
At the beginning of your end step, if you sacrificed one or more permanents this turn, Sawblade Skinripper deals that much damage to any target.

Spineseeker Centipede

When Spineseeker Centipede enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Delirium — Spineseeker Centipede gets +1/+2 and has vigilance as long as there are four or more card types among cards in your graveyard.

Zimone, All-Questioning

At the beginning of your end step, if a land entered the battlefield under your control this turn and you control a prime number of lands, create Primo, the Indivisible, a legendary 0/0 green and blue Fractal creature token, then put that many +1/+1 counters on it. (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, and 31 are prime numbers.)