Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Mortuary Mire

Mortuary Mire enters the battlefield tapped.
When Mortuary Mire enters the battlefield, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Bontu's Monument

Black creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Spymaster's Vault

Spymaster's Vault enters the battlefield tapped unless you control a Swamp.
{T}: Add {B}.
{B}, {T}: Target creature you control connives X, where X is the number of creatures that died this turn. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

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.

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Sol Ring

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Tomb Fortress

Tomb Fortress enters the battlefield tapped.
{T}: Add {B}.
{2}{B}{B}{B}, {T}, Exile Tomb Fortress: Mill four cards, then return a creature card from your graveyard to the battlefield. Activate only as a sorcery.

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Tocasia's Dig Site

{T}: Add {C}.
{3}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Phyrexian Arena

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

Victimize

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

Insatiable Avarice

Spree (Choose one or more additional costs.)
+ {2} — Search your library for a card, then shuffle and put that card on top.
+ {B}{B} — Target player draws three cards and loses 3 life.

Dread Presence

Whenever a Swamp enters the battlefield under your control, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Massacre Wurm

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Solemn Simulacrum

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

Black Sun's Twilight

Up to one target creature gets -X/-X until end of turn. If X is 5 or more, return a creature card with mana value X or less from your graveyard to the battlefield tapped.

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

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.

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Village Rites

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Arcane Signet

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

Crypt of Agadeem

Crypt of Agadeem enters the battlefield tapped.
{T}: Add {B}.
{2}, {T}: Add {B} for each black creature card in your graveyard.

Sign in Blood

Target player draws two cards and loses 2 life.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Chronomancer

Flying
Atomic Transmutation — {1}, {T}, Sacrifice another artifact: Draw a card.
Unearth {2}{B} ({2}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Night's Whisper

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Blood for Bones

As an additional cost to cast this spell, sacrifice a creature.
Return a creature card from your graveyard to the battlefield, then return another creature card from your graveyard to your hand.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Scion of Halaster

Commander creatures you own have "The first time you would draw a card each turn, instead look at the top two cards of your library. Put one of them into your graveyard and the other back on top of your library. Then draw a card."

Infernal Grasp

Destroy target creature. You lose 2 life.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Ashnod's Altar

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Urborg, Tomb of Yawgmoth

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

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters the battlefield, destroy up to one target creature and target player mills three cards.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Cemetery Tampering

Hideaway 5 (When this enchantment enters the battlefield, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
At the beginning of your upkeep, you may mill three cards. Then if there are twenty or more cards in your graveyard, you may play the exiled card without paying its mana cost.

Ophiomancer

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Noxious Gearhulk

Menace
When Noxious Gearhulk enters the battlefield, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Memorial to Folly

Memorial to Folly enters the battlefield tapped.
{T}: Add {B}.
{2}{B}, {T}, Sacrifice Memorial to Folly: Return target creature card from your graveyard to your hand.

Tormod, the Desecrator

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Swamp

Desert of the Glorified

Desert of the Glorified enters the battlefield tapped.
{T}: Add {B}.
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

Jet Medallion

Black spells you cast cost {1} less to cast.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Angel of Suffering

Flying
If damage would be dealt to you, prevent that damage and mill twice that many cards.