New Blood

As an additional cost to cast this spell, tap an untapped Vampire you control.
Gain control of target creature. Change the text of that creature by replacing all instances of one creature type with Vampire.

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.

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.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Stromkirk Captain

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

Rakish Heir

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

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.

Sol Ring

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.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Call the Bloodline

{1}, Discard a card: Create a 1/1 black Vampire Knight creature token with lifelink. Activate only once each turn.