Corrosive Mentor

Black creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Royal Assassin

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Swamp

Fodder Cannon

{4}, {T}, Sacrifice a creature: This artifact deals 4 damage to target creature.

Tattered Mummy

When this creature dies, each opponent loses 2 life.

Yoke of the Damned

Enchant creature
When a creature dies, destroy enchanted creature.

Leechridden Swamp

({T}: Add {B}.)
This land enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Disentomb

Return target creature card from your graveyard to your hand.

Scavenger Drake

Flying
Whenever another creature dies, you may put a +1/+1 counter on this creature.

Ravenous Harpy

Flying
{1}, Sacrifice another creature: Put a +1/+1 counter on this creature.

Kiku, Night's Flower

{2}{B}{B}, {T}: Target creature deals damage to itself equal to its power.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Demon's Horn

Whenever a player casts a black spell, you may gain 1 life.

Zhalfirin Void

When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {C}.

Infectious Host

When this creature dies, target player loses 2 life.

Shirei, Shizo's Caretaker

Whenever a creature with power 1 or less is put into your graveyard from the battlefield, you may return that card to the battlefield at the beginning of the next end step if Shirei is still on the battlefield.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Mind Slash

{B}, Sacrifice a creature: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.

Vizier of the Scorpion

When this creature enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
Zombie tokens you control have deathtouch.

Doomed Dissenter

When this creature dies, create a 2/2 black Zombie creature token.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Lazotep Reaver

When this creature enters, amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Demonic Tutor

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Neurok Stealthsuit

Equipped creature has shroud. (It can't be the target of spells or abilities.)
{U}{U}: Attach this Equipment to target creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Hell's Caretaker

{T}, Sacrifice a creature: Return target creature card from your graveyard to the battlefield. Activate only during your upkeep.