Sign in Blood

Target player draws two cards and loses 2 life.

Murder

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

During your turn, Blood Burglar has lifelink.(Damage dealt by this creature also causes you to gain that much life.)

Whenever Vicious Conquistador attacks, each opponent loses 1 life.

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

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

Flying
When Skymarch Bloodletter enters, target opponent loses 1 life and you gain 1 life.

Enchant creature
Enchanted creature gets +2/+2 as long as it's a Vampire. Otherwise, it gets -2/-2.