Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Torch the Tower

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Torch the Tower deals 2 damage to target creature or planeswalker. If this spell was bargained, instead it deals 3 damage to that permanent and you scry 1.
If a permanent dealt damage by Torch the Tower would die this turn, exile it instead.

Blazemire Verge

{T}: Add {B}.
{T}: Add {R}. Activate only if you control a Swamp or a Mountain.

Swamp

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.)

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

Duress

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

Extinction Event

Choose odd or even. Exile each creature with mana value of the chosen quality. (Zero is even.)

Sheoldred's Edict

Choose one —
• Each opponent sacrifices a nontoken creature.
• Each opponent sacrifices a creature token.
• Each opponent sacrifices a planeswalker.

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

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

Misery's Shadow

If a creature an opponent controls would die, exile it instead.
{1}: Misery's Shadow gets +1/+1 until end of turn.

Go Blank

Target player discards two cards. Then exile that player's graveyard.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

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.

Path of Peril

Cleave {4}{W}{B} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Destroy all creatures [with mana value 2 or less].

March of Wretched Sorrow

As an additional cost to cast this spell, you may exile any number of black cards from your hand. This spell costs {2} less to cast for each card exiled this way.
March of Wretched Sorrow deals X damage to target creature or planeswalker and you gain X life.

Reflection of Kiki-Jiki

{1}, {T}: Create a token that's a copy of another target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Fable of the Mirror-Breaker

(As this Saga enters and after your draw step, add a lore counter.)
I — Create a 2/2 red Goblin Shaman creature token with "Whenever this creature attacks, create a Treasure token."
II — You may discard up to two cards. If you do, draw that many cards.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Fable of the Mirror-Breaker // Reflection of Kiki-Jiki

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.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Unlicensed Hearse

{T}: Exile up to two target cards from a single graveyard.
Unlicensed Hearse's power and toughness are each equal to the number of cards exiled with it.
Crew 2

Blackcleave Cliffs

Blackcleave Cliffs enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.