Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Infernal Grasp

Destroy target creature. You lose 2 life.

Strangling Grasp

Enchant creature or planeswalker an opponent controls
At the beginning of your upkeep, enchanted permanent's controller sacrifices a nonland permanent of their choice, then that player loses 1 life.

Vengeful Strangler

Vengeful Strangler can't block.
When Vengeful Strangler dies, return it to the battlefield transformed under your control attached to target creature or planeswalker an opponent controls.

Vengeful Strangler // Strangling Grasp

Morkrut Behemoth

As an additional cost to cast this spell, sacrifice a creature or pay {1}{B}.
Menace (This creature can't be blocked except by two or more creatures.)

Bat Whisperer

When Bat Whisperer enters, if an opponent lost life this turn, create a 1/1 black Bat creature token with flying.

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Arrogant Outlaw

When Arrogant Outlaw enters, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

Hobbling Zombie

Deathtouch
When Hobbling Zombie dies, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

Swamp

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Stromkirk Bloodthief

At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on target Vampire you control.

Bloodtithe Collector

Flying
When this creature enters, if an opponent lost life this turn, each opponent discards a card.