Ethereal Armor

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

Piranha Fly

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.)

Silent Hallcreeper

This creature can't be blocked.
Whenever this creature deals combat damage to a player, choose one that hasn't been chosen —
• Put two +1/+1 counters on this creature.
• Draw a card.
• This creature becomes a copy of another target creature you control.

Stalked Researcher

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

Stay Hidden, Stay Silent

Manifest

Enchant creature
When this Aura 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.

The Tale of Tamiyo

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I, II, III — Mill two cards. If two cards that share a card type were milled this way, draw a card and repeat this process.
IV — Exile any number of target instant, sorcery, and/or Tamiyo planeswalker cards from your graveyard. Copy them. You may cast any number of the copies.

Tunnel Surveyor

Glimmer

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

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.)

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.

Underwater Tunnel // Slimy Aquarium

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.)

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.)

Exorcise

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

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.)

Spirit

Unwilling Vessel

Vigilance
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, put a possession counter on this creature.
When this creature dies, create an X/X blue Spirit creature token with flying, where X is the number of counters on this creature.

Vanish from Sight

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

Appendage Amalgam

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

Duskmourn: House of Horror