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.

Scorching Dragonfire

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

Unsettling Twins

When Unsettling Twins 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.)

Reluctant Role Model

Survival — At the beginning of your second main phase, if Reluctant Role Model is tapped, put a flying, lifelink, or +1/+1 counter on it.
Whenever Reluctant Role Model or another creature you control dies, if it had counters on it, put those counters on up to one target creature.

Vicious Clown

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

Turn Inside Out

Target creature gets +3/+0 until end of turn. When it dies this turn, 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.)

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

Arabella, Abandoned Doll

Whenever Arabella, Abandoned Doll attacks, it deals X damage to each opponent and you gain X life, where X is the number of creatures you control with power 2 or less.

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.

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.

Mountain

Enduring Innocence

Lifelink
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.
When Enduring Innocence dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Plains

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.)

Ripchain Razorkin

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

Ragged Playmate

{1}, {T}: Target creature with power 2 or less can't be blocked this turn.

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.)

Cult Healer

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, Cult Healer gains lifelink until end of turn.

Impossible Inferno

Impossible Inferno deals 6 damage to target creature.
Delirium — If there are four or more card types among cards in your graveyard, exile the top card of your library. You may play it until the end of your next turn.