Mortify

Mourning Thrull

({W/B} can be paid with either {W} or {B}.)
Flying
Whenever Mourning Thrull deals damage, you gain that much life.

Strands of Undeath

Enchant creature
When Strands of Undeath enters, target player discards two cards.
{B}: Regenerate enchanted creature.

Skeletal Vampire

Flying
When Skeletal Vampire enters, create two 1/1 black Bat creature tokens with flying.
{3}{B}{B}, Sacrifice a Bat: Create two 1/1 black Bat creature tokens with flying.
Sacrifice a Bat: Regenerate Skeletal Vampire.

Poisonbelly Ogre

Whenever another creature enters, its controller loses 1 life.

Teysa, Orzhov Scion

Sacrifice three white creatures: Exile target creature.
Whenever another black creature you control dies, create a 1/1 white Spirit creature token with flying.

Orzhov Guildmage

{2}{W}: Target player gains 1 life.
{2}{B}: Each player loses 1 life.

Blind Hunter

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When Blind Hunter enters or the creature it haunts dies, target player loses 2 life and you gain 2 life.

Infectious Host

When Infectious Host dies, target player loses 2 life.

Thoughtpicker Witch

{1}, Sacrifice a creature: Look at the top two cards of target opponent's library, then exile one of them.

Ostiary Thrull

Castigate

Target opponent reveals their hand. You choose a nonland card from it and exile that card.

Plagued Rusalka

{B}, Sacrifice a creature: Target creature gets -1/-1 until end of turn.

Martyred Rusalka

{W}, Sacrifice a creature: Target creature can't attack this turn.

Souls of the Faultless

Defender (This creature can't attack.)
Whenever Souls of the Faultless is dealt combat damage, you gain that much life and attacking player loses that much life.

Pillory of the Sleepless

Enchant creature
Enchanted creature can't attack or block.
Enchanted creature has "At the beginning of your upkeep, you lose 1 life."

Orzhov Basilica

Orzhov Basilica enters tapped.
When Orzhov Basilica enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Orzhova, the Church of Deals

{T}: Add {C}.
{3}{W}{B}, {T}: Target player loses 1 life and you gain 1 life.

Belfry Spirit

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When Belfry Spirit enters or the creature it haunts dies, create two 1/1 black Bat creature tokens with flying.

Plains

Shrieking Grotesque

Flying
When Shrieking Grotesque enters, if {B} was spent to cast it, target player discards a card.

Festival of the Guildpact

Prevent the next X damage that would be dealt to you this turn.
Draw a card.

Swamp

Orzhov Euthanist

Haunt (When this creature dies, exile it haunting target creature.)
When Orzhov Euthanist enters or the creature it haunts dies, destroy target creature that was dealt damage this turn.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Agent of Masks

At the beginning of your upkeep, each opponent loses 1 life. You gain life equal to the life lost this way.