Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Arcane Signet

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

Plains

Athreos, Shroud-Veiled

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
At the beginning of your end step, put a coin counter on another target creature.
Whenever a creature with a coin counter on it dies or is put into exile, return that card to the battlefield under your control.

Tablet of the Guilds

As Tablet of the Guilds enters the battlefield, choose two colors.
Whenever you cast a spell, if it's at least one of the chosen colors, you gain 1 life for each of the chosen colors it is.

Soul Warden

Whenever another creature enters the battlefield, you gain 1 life.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Ravenous Chupacabra

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Athreos, God of Passage

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Whenever another creature you own dies, return it to your hand unless target opponent pays 3 life.

Orzhov Signet

Daxos the Returned

Whenever you cast an enchantment spell, you get an experience counter.
{1}{W}{B}: Create a white and black Spirit enchantment creature token. It has "This creature's power and toughness are each equal to the number of experience counters you have."

Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Grave Pact

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

Swamp

Souls of the Faultless

Defender (This creature can't attack.)
Whenever Souls of the Faultless is dealt combat damage, you gain that much life and attacking player loses that much life.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)