Cordial Vampire

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

Champion of Dusk

When Champion of Dusk enters, you draw X cards and you lose X life, where X is the number of Vampires you control.

Edgar Markov

Eminence — Whenever you cast another Vampire spell, if Edgar Markov is in the command zone or on the battlefield, create a 1/1 black Vampire creature token.
First strike, haste
Whenever Edgar Markov attacks, put a +1/+1 counter on each Vampire you control.

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.)

Charismatic Conqueror

Vigilance
Whenever an artifact or creature an opponent controls enters untapped, they may tap that permanent. If they don't, you create a 1/1 white Vampire creature token with lifelink.

Voldaren Estate

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a Vampire spell.
{5}, {T}: Create a Blood token. This ability costs {1} less to activate for each Vampire you control. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Malakir Bloodwitch

Flying, protection from white
When Malakir Bloodwitch enters, each opponent loses life equal to the number of Vampires you control. You gain life equal to the life lost this way.

Stromkirk Captain

First strike
Other Vampire creatures you control get +1/+1 and have first strike.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Vampire Socialite

Menace (This creature can't be blocked except by two or more creatures.)
When Vampire Socialite enters, if an opponent lost life this turn, put a +1/+1 counter on each other Vampire you control.
As long as an opponent lost life this turn, each other Vampire you control enters with an additional +1/+1 counter on it.

Captivating Vampire

Other Vampire creatures you control get +1/+1.
Tap five untapped Vampires you control: Gain control of target creature. It becomes a Vampire in addition to its other types.

Anowon, the Ruin Sage

At the beginning of your upkeep, each player sacrifices a non-Vampire creature of their choice.

Sanctum Seeker

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

Olivia's Wrath

Each non-Vampire creature gets -X/-X until end of turn, where X is the number of Vampires you control.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)