Cruel Celebrant

Whenever Cruel Celebrant or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Mavren Fein, Dusk Apostle

Whenever one or more nontoken Vampires you control attack, create a 1/1 white Vampire creature token with lifelink.

Sanctum Seeker

Whenever a Vampire you control attacks, each opponent loses 1 life and you gain 1 life.

Cordial Vampire

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

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 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.)

Legion Lieutenant

Indulgent Aristocrat

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

Elenda, the Dusk Rose

Lifelink
Whenever another creature dies, put a +1/+1 counter on Elenda, the Dusk Rose.
When Elenda dies, create X 1/1 white Vampire creature tokens with lifelink, where X is Elenda's power.