Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Have

Lord of the Accursed

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

Tainted Adversary

Deathtouch
When Tainted Adversary enters, you may pay {2}{B} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on Tainted Adversary, then create twice that many 2/2 black Zombie creature tokens with decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Midnight Reaper

Whenever a nontoken creature you control dies, this creature deals 1 damage to you and you draw a card.

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.)

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Champion of the Perished

Whenever another Zombie you control enters, put a +1/+1 counter on Champion of the Perished.

Dark Salvation

Target player creates X 2/2 black Zombie creature tokens, then up to one target creature gets -1/-1 until end of turn for each Zombie that player controls.

Lantern of the Lost

When Lantern of the Lost enters, exile target card from a graveyard.
{1}, {T}, Exile Lantern of the Lost: Exile all cards from all graveyards, then draw a card.

Headless Rider

Whenever Headless Rider or another nontoken Zombie you control dies, create a 2/2 black Zombie creature token.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Heartless Act

Choose one —
• Destroy target creature with no counters on it.
• Remove up to three counters from target creature.

Death Baron

Skeletons you control and other Zombies you control get +1/+1 and have deathtouch. (Any amount of damage they deal to a creature is enough to destroy it.)

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Lazotep Reaver

When Lazotep Reaver 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.)

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.

Swamp

Necromentia

Choose a card name other than a basic land card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then creates a 2/2 black Zombie creature token for each card exiled from their hand this way.

Witch's Vengeance

Creatures of the creature type of your choice get -3/-3 until end of turn.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.