Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Blade of the Bloodchief

Whenever a creature dies, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead.
Equip {1}

Stromkirk Noble

Stromkirk Noble can't be blocked by Humans.
Whenever Stromkirk Noble deals combat damage to a player, put a +1/+1 counter on it.

Vampire Nighthawk

Stromkirk Captain

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

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Bloodghast

Bloodghast can't block.
Bloodghast has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return Bloodghast from your graveyard to the battlefield.

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.

Feast of Blood

Cast this spell only if you control two or more Vampires.
Destroy target creature. You gain 4 life.

Rakish Heir

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