Pestilence Demon

Flying
{B}: This creature deals 1 damage to each creature and each player.

Necropolis Regent

Flying
Whenever a creature you control deals combat damage to a player, put that many +1/+1 counters on it.

Strands of Night

{B}{B}, Pay 2 life, Sacrifice a Swamp: Return target creature card from your graveyard to the battlefield.

Abyssal Gatekeeper

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

Visara the Dreadful

Flying
{T}: Destroy target creature. It can't be regenerated.

Sign in Blood

Target player draws two cards and loses 2 life.

Midnight Reaper

Whenever a nontoken creature you control dies, this creature deals 1 damage to you and you draw a card.

Thrull Parasite

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
{T}, Pay 2 life: Remove a counter from target nonland permanent.

Phyrexian Gargantua

When this creature enters, you draw two cards and you lose 2 life.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik.

Entreat the Dead

Return X target creature cards from your graveyard to the battlefield.
Miracle {X}{B}{B} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with this artifact to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with this artifact. It gains haste. Exile it at the beginning of the next end step.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Abhorrent Overlord

Flying
When this creature enters, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

Rescue from the Underworld

As an additional cost to cast this spell, sacrifice a creature.
Choose target creature card in your graveyard. Return that card and the sacrificed card to the battlefield under your control at the beginning of your next upkeep. Exile Rescue from the Underworld.

Liliana's Shade

When this creature enters, you may search your library for a Swamp card, reveal it, put it into your hand, then shuffle.
{B}: This creature gets +1/+1 until end of turn.

Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)