Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Dusk Legion Zealot

When Dusk Legion Zealot enters, you draw a card and you lose 1 life.

Nullpriest of Oblivion

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Lifelink
Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, if it was kicked, return target creature card from your graveyard to the battlefield.

Shadow Alley Denizen

Whenever another black creature you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Master of Dark Rites

{T}, Sacrifice another creature: Add {B}{B}{B}. Spend this mana only to cast Vampire, Cleric, and/or Demon spells.

Dark Impostor

{4}{B}{B}: Exile target creature and put a +1/+1 counter on Dark Impostor.
Dark Impostor has all activated abilities of all creature cards exiled with it.

Timothar, Baron of Bats

Ward—Discard a card.
Whenever another nontoken Vampire you control dies, you may pay {1} and exile it. If you do, create a 1/1 black Bat creature token with flying. It gains "When this creature deals combat damage to a player, sacrifice it and return the exiled card to the battlefield tapped."

Acolyte of Aclazotz

{T}, Sacrifice another creature or artifact: Each opponent loses 1 life and you gain 1 life.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Callous Bloodmage

When Callous Bloodmage enters, choose one —
• Create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."
• You draw a card and you lose 1 life.
• Exile target player's graveyard.

Nocturnal Feeder

Flying
When Nocturnal Feeder dies, each opponent loses 2 life and you gain 2 life.

Vermin Gorger

{T}, Sacrifice another creature: Each opponent loses 2 life and you gain 2 life.

Markov Baron

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Lifelink
Other Vampires you control get +1/+1.
Madness {2}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Vraan, Executioner Thane

Whenever one or more other creatures you control die, each opponent loses 2 life and you gain 2 life. This ability triggers only once each turn.

Indulgent Aristocrat

Lifelink
{2}, Sacrifice a creature: Put a +1/+1 counter on each Vampire you control.

Cordial Vampire

Whenever Cordial Vampire or another creature dies, put a +1/+1 counter on each Vampire you control.

Silversmote Ghoul

At the beginning of your end step, if you gained 3 or more life this turn, return Silversmote Ghoul from your graveyard to the battlefield tapped.
{1}{B}, Sacrifice Silversmote Ghoul: Draw a card.

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.