Monstrous Emergence

As an additional cost to cast this spell, choose a creature you control or reveal a creature card from your hand.
Monstrous Emergence deals damage equal to the power of the creature you chose or the card you revealed to target creature.

Horrid Vigor

Target creature gains deathtouch and indestructible until end of turn.

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.)

Patched Plaything

Double strike
Patched Plaything enters with two -1/-1 counters on it if you cast it from your hand.

Forest

Vicious Clown

Whenever another creature you control with power 2 or less enters, Vicious Clown gets +2/+0 until end of turn.

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.)

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.

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

Gremlin Tamer

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

Grasping Longneck

Reach
When Grasping Longneck dies, you gain 2 life.

Cryptid Inspector

Vigilance
Whenever a face-down permanent you control enters and whenever Cryptid Inspector or another permanent you control is turned face up, put a +1/+1 counter on Cryptid Inspector.

Malevolent Chandelier

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

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.)

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.)

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.

Cathartic Parting

The owner of target artifact or enchantment an opponent controls shuffles it into their library. You may shuffle up to four target cards from your graveyard into your library.

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.)

Cautious Survivor

Survival — At the beginning of your second main phase, if Cautious Survivor is tapped, you gain 2 life.

Lakeside Shack

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

Friendly Teddy

When Friendly Teddy dies, each player draws a card.

Strangled Cemetery

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

Island

Rampaging Soulrager

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

Etched Cornfield

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

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

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.

Collected Company

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in any order.

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.

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.)

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.)

Fear of Exposure

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

Fear of Surveillance

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

Duskmourn's Domination

Enchant creature
You control enchanted creature.
Enchanted creature gets -3/-0 and loses all abilities.