Arcane Signet

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

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Thought Vessel

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

Dark Ritual

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature of their choice.

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.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Sol Ring

Gray Merchant of Asphodel

When Gray Merchant of Asphodel 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.)

Damnation

Destroy all creatures. They can't be regenerated.

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

Commander's Sphere

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

Command Tower

Sonic Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Untap another target artifact.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{3}, {T}: Target creature can't be blocked this turn.

Mountain

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Valgavoth, Harrower of Souls

Flying
Ward—Pay 2 life.
Whenever an opponent loses life for the first time during each of their turns, put a +1/+1 counter on Valgavoth, Harrower of Souls and draw a card.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Reliquary Tower

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Terminate

Destroy target creature. It can't be regenerated.

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Mayhem Devil

Whenever a player sacrifices a permanent, Mayhem Devil deals 1 damage to any target.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

Orcish Bowmasters

Flash
When Orcish Bowmasters enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Rakdos, Patron of Chaos

Flying, trample
At the beginning of your end step, target opponent may sacrifice two nonland, nontoken permanents of their choice. If they don't, you draw two cards.