Mire's Grasp

Enchant creature
Enchanted creature gets -3/-3.

Gray Merchant of Asphodel

When this creature 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.)

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.)

Tymaret Calls the Dead

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Mill three cards. Then you may exile a creature or enchantment card from your graveyard. If you do, create a 2/2 black Zombie creature token.
III — You gain X life and scry X, where X is the number of Zombies you control.

Undead Augur

Whenever this creature or another Zombie you control dies, you draw a card and you lose 1 life.

Dreadhorde Invasion

At the beginning of your upkeep, you lose 1 life and 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.)
Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.

Lord of the Accursed

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

Mindwrack Harpy

Flying
At the beginning of combat on your turn, each player mills three cards.

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Graf Harvest

Zombies you control have menace. (They can't be blocked except by two or more creatures.)
{3}{B}, Exile a creature card from your graveyard: Create a 2/2 black Zombie creature token.

Cryptbreaker

{1}{B}, {T}, Discard a card: Create a 2/2 black Zombie creature token.
Tap three untapped Zombies you control: You draw a card and you lose 1 life.

Agent of Erebos

Constellation — Whenever this creature or another enchantment you control enters, exile target player's graveyard.

Thoughtrender Lamia

Constellation — Whenever this creature or another enchantment you control enters, each opponent discards a card.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Liliana's Mastery

Zombies you control get +1/+1.
When this enchantment enters, create two 2/2 black Zombie creature tokens.

Blightcaster

Whenever you cast an enchantment spell, you may have target creature get -2/-2 until end of turn.

Nighthowler

Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Aphemia, the Cacophony

Flying
At the beginning of your end step, you may exile an enchantment card from your graveyard. If you do, create a 2/2 black Zombie creature token.

The Eldest Reborn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker of their choice.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Grim Guardian

Constellation — Whenever this creature or another enchantment you control enters, each opponent loses 1 life.

Erebos, Bleak-Hearted

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature.
Whenever another creature you control dies, you may pay 2 life. If you do, draw a card.
{1}{B}, Sacrifice another creature: Target creature gets -2/-1 until end of turn.