Swamp

Hopeless Nightmare

When this enchantment enters, each opponent discards a card and loses 2 life.
When this enchantment is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice this enchantment.

Drown in Sorrow

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Trespasser's Curse

Enchant player
Whenever a creature enchanted player controls enters, that player loses 1 life and you gain 1 life.

Vampire's Kiss

Target player loses 2 life and you gain 2 life. Create two Blood tokens. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Jagged Barrens

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {B} or {R}.

Bump in the Night

Target opponent loses 3 life.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Black Mage's Rod

Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.)
Equipped creature gets +1/+0, has "Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent," and is a Wizard in addition to its other types.
Equip {3}

Cornered by Black Mages

Target opponent sacrifices a creature of their choice.
Create a 0/1 black Wizard creature token with "Whenever you cast a noncreature spell, this token deals 1 damage to each opponent."

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Night's Whisper

Soul Reap

Destroy target nongreen creature. Its controller loses 3 life if you've cast another black spell this turn.

Duress

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

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Risky Shortcut

Draw two cards. Each player loses 2 life.

Nihil Spellbomb

{T}, Sacrifice this artifact: Exile target player's graveyard.
When this artifact is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Sign in Blood

Target player draws two cards and loses 2 life.

Nezumi Road Captain

Menace
Vehicles you control have menace. (They can't be blocked except by two or more creatures.)

Okiba Reckoner Raid

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Each opponent loses 1 life and you gain 1 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.