Alms of the Vein

Target opponent loses 3 life and you gain 3 life.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Blister Beetle

When Blister Beetle enters, target creature gets -1/-1 until end of turn.

Skirge Familiar

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Audacious Thief

Whenever Audacious Thief attacks, you draw a card and you lose 1 life.

Bitter Revelation

Look at the top four cards of your library. Put two of them into your hand and the rest into your graveyard. You lose 2 life.

Crossroads Candleguide

When Crossroads Candleguide enters, exile up to one target card from a graveyard.
{2}: Add one mana of any color.

Honored Heirloom

{T}: Add one mana of any color.
{2}, {T}: Exile target card from a graveyard.

Bog Initiate

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Aid the Fallen

Choose one or both —
• Return target creature card from your graveyard to your hand.
• Return target planeswalker card from your graveyard to your hand.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Chainer's Edict

Target player sacrifices a creature of their choice.
Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Songs of the Damned

Add {B} for each creature card in your graveyard.

Alloy Myr

Skittering Heartstopper

{B}: Skittering Heartstopper gains deathtouch until end of turn.

Fountain of Ichor

{T}: Add one mana of any color.
{3}: Fountain of Ichor becomes a 3/3 Dinosaur artifact creature until end of turn.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Blistergrub

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When Blistergrub dies, each opponent loses 2 life.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Blood Pet

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature of their choice.

Sanitarium Skeleton

{2}{B}: Return Sanitarium Skeleton from your graveyard to your hand.

Basal Thrull

Accursed Spirit

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Predatory Nightstalker

When Predatory Nightstalker enters, you may have target opponent sacrifice a creature of their choice.

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Blood Vassal

Overeager Apprentice

Discard a card, Sacrifice Overeager Apprentice: Add {B}{B}{B}.

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Eviscerate

Gangrenous Zombies

{T}, Sacrifice Gangrenous Zombies: Gangrenous Zombies deals 1 damage to each creature and each player. If you control a snow Swamp, Gangrenous Zombies deals 2 damage to each creature and each player instead.

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Balustrade Spy

Flying
When Balustrade Spy enters, target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Sign in Blood

Target player draws two cards and loses 2 life.

Baleful Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Enchanted creature gets +1/+1 and has deathtouch.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Twisted Abomination

{B}: Regenerate Twisted Abomination. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Bog Witch

Afflict

Target creature gets -1/-1 until end of turn.
Draw a card.

Dark Ritual

Swamp

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Letter of Acceptance

{T}: Add one mana of any color.
{2}, {T}, Sacrifice Letter of Acceptance: Draw a card.

Barrier of Bones

Defender
When Barrier of Bones enters, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)