Have

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.)

Defile

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

Wrench Mind

Target player discards two cards unless they discard an artifact card.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Sinister Possession

Enchant creature
Whenever enchanted creature attacks or blocks, its controller loses 2 life.

Duress

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

Liliana's Specter

Flying
When this creature enters, each opponent discards a card.

Trench Stalker

As long as you've drawn two or more cards this turn, this creature has deathtouch and lifelink.

Thorn of the Black Rose

Deathtouch
When this creature enters, you become the monarch.

Swamp

Cuombajj Witches

{T}: This creature deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Choking Sands

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Chittering Rats

When this creature enters, target opponent puts a card from their hand on top of their library.

Victim of Night

Destroy target non-Vampire, non-Werewolf, non-Zombie creature.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Whisper Agent

Flash
When this creature enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Insubordination

Enchant creature
At the beginning of the end step of enchanted creature's controller, this Aura deals 2 damage to that player unless that creature attacked this turn.

Geth's Verdict

Target player sacrifices a creature of their choice and loses 1 life.

Ashes to Ashes

Exile two target nonartifact creatures. Ashes to Ashes deals 5 damage to you.

Getting

Barren Moor

This land enters tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Death Watch

Enchant creature
When enchanted creature dies, its controller loses life equal to its power and you gain life equal to its toughness.