Stay Hidden, Stay Silent

Enchant creature
When Stay Hidden, Stay Silent enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{4}{U}{U}: Shuffle enchanted creature into its owner's library, then manifest dread. Activate only as a sorcery.

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.

Ghostly Dancers

Flying
When Ghostly Dancers enters, return an enchantment card from your graveyard to your hand or unlock a locked door of a Room you control.
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, create a 3/1 white Spirit creature token with flying.

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.)

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.

Clammy Prowler

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

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

Plains

Terramorphic Expanse

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

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.)

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.)

Glimmerburst

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

Floodfarm Verge

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

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.)

Creeping Peeper

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

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.

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.

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.)

Shepherding Spirits

Flying
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Fear of Immobility

When Fear of Immobility 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.)

Tunnel Surveyor

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

Erratic Apparition

Flying, vigilance
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, Erratic Apparition gets +1/+1 until end of turn.

Island

Ghostly Keybearer

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

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.

Trapped in the Screen

Ward {2} (Whenever this enchantment becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When Trapped in the Screen enters, exile target artifact, creature, or enchantment an opponent controls until Trapped in the Screen leaves the battlefield.

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.)

Gremlin Tamer

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

Ethereal Armor

Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control and has first strike.

Unnerving Grasp

Return up to one target nonland permanent to its owner's hand. 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.)