Bloodthirsty Adversary

Haste
When Bloodthirsty Adversary enters, you may pay {2}{R} any number of times. When you pay this cost one or more times, put that many +1/+1 counters on Bloodthirsty Adversary, then exile up to that many target instant and/or sorcery cards with mana value 3 or less from your graveyard and copy them. You may cast any number of the copies without paying their mana costs.

Olivia Voldaren

Flying
{1}{R}: Olivia Voldaren deals 1 damage to another target creature. That creature becomes a Vampire in addition to its other types. Put a +1/+1 counter on Olivia Voldaren.
{3}{B}{B}: Gain control of target Vampire for as long as you control Olivia Voldaren.

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.

Bloodsworn Steward

Flying
Commander creatures you control get +2/+2 and have haste.

Dark Ritual

Kalastria Highborn

Whenever this creature or another Vampire you control dies, you may pay {B}. If you do, target player loses 2 life and you gain 2 life.

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."

Stromkirk Captain

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

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.

Vampire of the Dire Moon

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)