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.

Scorching Dragonfire

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

Fear of Burning Alive

When Fear of Burning Alive enters, it deals 4 damage to each opponent.
Delirium — Whenever a source you control deals noncombat damage to an opponent, if there are four or more card types among cards in your graveyard, Fear of Burning Alive deals that amount of damage to target creature that player controls.

Mountain

Commune with Evil

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard. You gain 3 life.

Cackling Slasher

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

Infernal Phantom

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, Infernal Phantom gets +2/+0 until end of turn.
When Infernal Phantom dies, it deals damage equal to its power to any target.

Neglected Manor

Neglected Manor enters tapped unless a player has 13 or less life.
{T}: Add {W} or {B}.

Shattered Yard

(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.)
At the beginning of your end step, this Room deals 1 damage to each opponent.

Glassworks

(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.)
When you unlock this door, this Room deals 4 damage to target creature an opponent controls.

Glassworks // Shattered Yard

Trial of Agony

Choose two target creatures controlled by the same opponent. That player chooses one of those creatures. Trial of Agony deals 5 damage to that creature, and the other can't block this turn.

Undead Sprinter

Trample, haste
You may cast Undead Sprinter from your graveyard if a non-Zombie creature died this turn. If you do, Undead Sprinter enters with a +1/+1 counter on it.

Innocuous Rat

When Innocuous Rat 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.)

Fear of Lost Teeth

When Fear of Lost Teeth dies, it deals 1 damage to any target and you gain 1 life.

Killer's Mask

When Killer's Mask enters, manifest dread, then attach Killer's Mask to that creature. (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.)
Equipped creature has menace.
Equip {2}

Norin, Swift Survivalist

Norin, Swift Survivalist can't block.
Whenever a creature you control becomes blocked, you may exile it. You may play that card from exile this turn.

Most Valuable Slayer

Whenever you attack, target attacking creature gets +1/+0 and gains first strike until end of turn.

Enduring Tenacity

Whenever you gain life, target opponent loses that much life.
When Enduring Tenacity 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.)

Sporogenic Infection

Enchant creature
When Sporogenic Infection enters, target player sacrifices a creature other than enchanted creature.
When enchanted creature is dealt damage, destroy it.

Swamp

Piggy Bank

When Piggy Bank dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Widow's Walk

(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.)
Whenever a creature you control attacks alone, it gets +1/+0 and gains deathtouch until end of turn.

Derelict Attic

(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.)
When you unlock this door, you draw two cards and you lose 2 life.

Derelict Attic // Widow's Walk

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.