Underworld Connections

Enchant land
Enchanted land has "{T}, Pay 1 life: Draw a card."

Witch's Vengeance

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

Geth's Verdict

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

Hymn to Tourach

Target player discards two cards at random.

Lashwrithe

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each Swamp you control.
Equip {B/P}{B/P} ({B/P} can be paid with either {B} or 2 life.)

Duress

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

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.

Swamp

Slaughter

Buyback—Pay 4 life. (You may pay 4 life in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target nonblack creature. It can't be regenerated.

Victim of Night

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

Gatekeeper of Malakir

Kicker {B} (You may pay an additional {B} as you cast this spell.)
When this creature enters, if it was kicked, target player sacrifices a creature of their choice.

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Defile

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

Bile Blight

Target creature and all other creatures with the same name as that creature get -3/-3 until end of turn.

Stench of Evil

Destroy all Plains. For each land destroyed this way, Stench of Evil deals 1 damage to that land's controller unless they pay {2}.

Perish

Destroy all green creatures. They can't be regenerated.

Pharika's Libation

Choose one —
• Target opponent sacrifices a creature of their choice.
• Target opponent sacrifices an enchantment of their choice.

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.)

Thought Distortion

This spell can't be countered.
Target opponent reveals their hand. Exile all noncreature, nonland cards from that player's hand and graveyard.

Malicious Affliction

Morbid — When you cast this spell, if a creature died this turn, you may copy Malicious Affliction and may choose a new target for the copy.
Destroy target nonblack creature.