Patron of the Vein

Flying
When Patron of the Vein enters the battlefield, destroy target creature an opponent controls.
Whenever a creature an opponent controls dies, exile it and put a +1/+1 counter on each Vampire you control.

Rakdos Signet

Markov Enforcer

Whenever Markov Enforcer or another Vampire enters the battlefield under your control, Markov Enforcer fights up to one target creature an opponent controls.
Whenever a creature dealt damage by Markov Enforcer this turn dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Anje, Maid of Dishonor

Whenever Anje, Maid of Dishonor and/or one or more other Vampires enter the battlefield under your control, create a Blood token. This ability triggers only once each turn. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 life.

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Blood Artist

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

Strefan, Maurer Progenitor

Flying
At the beginning of your end step, create a Blood token for each player who lost life this turn.
Whenever Strefan attacks, you may sacrifice two Blood tokens. If you do, you may put a Vampire card from your hand onto the battlefield tapped and attacking. It gains indestructible until end of turn.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Butcher of Malakir

Flying
Whenever Butcher of Malakir or another creature you control dies, each opponent sacrifices a creature.