Absorb Vis

Target player loses 4 life and you gain 4 life.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Leonin Relic-Warder

When this creature enters, you may exile target artifact or enchantment.
When this creature leaves the battlefield, return the exiled card to the battlefield under its owner's control.

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.)

Cackling Slasher

Deathtouch
This creature enters with a +1/+1 counter on it if a creature died this turn.

Lionheart Glimmer

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever you attack, creatures you control get +1/+1 until end of turn.

Split Up

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

Murder

Widow's Walk

Whenever a creature you control attacks alone, it gets +1/+0 and gains deathtouch 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.)

Derelict Attic

When you unlock this door, you draw two cards and 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.)

Derelict Attic // Widow's Walk

Fear of Lost Teeth

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

Dragon's Presence

Dragon's Presence deals 5 damage to target attacking or blocking creature.

Plains

Swamp

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 this enchantment enters, exile target artifact, creature, or enchantment an opponent controls until this enchantment leaves the battlefield.

Quest for the Gravelord

Whenever a creature dies, you may put a quest counter on this enchantment.
Remove three quest counters from this enchantment and sacrifice it: Create a 5/5 black Zombie Giant creature token.

Nowhere to Run

Flash
When this enchantment enters, target creature an opponent controls gets -3/-3 until end of turn.
Creatures your opponents control can be the targets of spells and abilities as though they didn't have hexproof. Ward abilities of those creatures don't trigger.

Cracked Skull

Enchant creature
When this Aura enters, look at target player's hand. You may choose a nonland card from it. That player discards that card.
When enchanted creature is dealt damage, destroy it.

Unyielding Krumar

{1}{W}: This creature gains first strike until end of turn.

Dashing Bloodsucker

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, this creature gets +2/+0 and gains lifelink until end of turn.

Veteran Survivor

Survival — At the beginning of your second main phase, if this creature is tapped, exile up to one target card from a graveyard.
As long as there are three or more cards exiled with this creature, it gets +3/+3 and has hexproof. (It can't be the target of spells or abilities your opponents control.)

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

Appendage Amalgam

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

Ghostly Dancers

Flying
When this creature 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.

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.

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.)

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.

Last Gasp

Target creature gets -3/-3 until end of turn.

Splitskin Doll

When this creature enters, draw a card. Then discard a card unless you control another creature with power 2 or less.