Swamp

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Anoint with Affliction

Exile target creature if it has mana value 3 or less.
Corrupted — Exile that creature instead if its controller has three or more poison counters.

Archfiend of the Dross

Flying
Archfiend of the Dross enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from Archfiend of the Dross. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.

Restless Reef

Restless Reef enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Restless Reef becomes a 4/4 blue and black Shark creature with deathtouch. It's still a land.
Whenever Restless Reef attacks, target player mills four cards.

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Go for the Throat

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Ritual Chamber

When you unlock this door, create a 6/6 black Demon creature token with flying.
(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.)

Unholy Annex

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life and you gain 2 life. Otherwise, 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.)

Unholy Annex // Ritual Chamber

Shoot the Sheriff

Destroy target non-outlaw creature. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. Everyone else is fair game.)

Cut Down

Destroy target creature with total power and toughness 5 or less.

Unstoppable Slasher

Deathtouch
Whenever Unstoppable Slasher deals combat damage to a player, they lose half their life, rounded up.
When Unstoppable Slasher dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Darkslick Shores

Darkslick Shores enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.