Scion of Opulence

Whenever Scion of Opulence or another nontoken Vampire you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
{R}, Sacrifice two artifacts: Exile the top card of your library. You may play that card this turn.

Bishop of the Bloodstained

When Bishop of the Bloodstained enters, target opponent loses 1 life for each Vampire 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.)

Rakish Heir

Whenever a Vampire you control deals combat damage to a player, put a +1/+1 counter on it.

Mavren Fein, Dusk Apostle

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

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.

Legion Vanguard

{1}, Sacrifice another creature: Legion Vanguard explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Legion Lieutenant

Cordial Vampire

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

Sanctum Seeker

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

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.

Dominating Vampire

When Dominating Vampire enters, gain control of target creature with mana value less than or equal to the number of Vampires you control until end of turn. Untap that creature. It gains haste until end of turn.

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Voldaren Ambusher

When Voldaren Ambusher enters, if an opponent lost life this turn, it deals X damage to up to one target creature or planeswalker, where X is the number of Vampires you control.

Order of Sacred Dusk

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.)
Flying, lifelink, haste
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Other Vampires you control have exalted.

Clavileño, First of the Blessed

Whenever you attack, target attacking Vampire that isn't a Demon becomes a Demon in addition to its other types. It gains "When this creature dies, draw a card and create a tapped 4/3 white and black Vampire Demon creature token with flying."

Stromkirk Captain

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

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.

Midnight Arsonist

When Midnight Arsonist enters, destroy up to X target artifacts without mana abilities, where X is the number of Vampires you control.

Baron Bertram Graywater

Whenever one or more tokens you control enter, create a 1/1 black Vampire Rogue creature token with lifelink. This ability triggers only once each turn.
{1}{B}, Sacrifice another creature or artifact: Draw a card.

Bishop of Binding

When Bishop of Binding enters, exile target creature an opponent controls until Bishop of Binding leaves the battlefield.
Whenever Bishop of Binding attacks, target Vampire gets +X/+X until end of turn, where X is the power of the exiled card.

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.

Forerunner of the Legion

When Forerunner of the Legion enters, you may search your library for a Vampire card, reveal it, then shuffle and put that card on top.
Whenever another Vampire you control enters, target creature gets +1/+1 until end of turn.

Master of Dark Rites

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

Crossway Troublemakers

Attacking Vampires you control have deathtouch and lifelink.
Whenever a Vampire you control dies, you may pay 2 life. If you do, draw a card.

Dusk Legion Zealot

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

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.