Vampire Nighthawk

Flying
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.)

Mortify

Elenda, the Dusk Rose

Lifelink
Whenever another creature dies, put a +1/+1 counter on Elenda.
When Elenda dies, create X 1/1 white Vampire creature tokens with lifelink, where X is Elenda's power.

Indulgent Aristocrat

Lifelink
{2}, Sacrifice a creature: Put a +1/+1 counter on each Vampire you control.

Mavren Fein, Dusk Apostle

Whenever one or more nontoken Vampires you control attack, create a 1/1 white Vampire creature token with lifelink.

Legion Lieutenant

Champion of Dusk

When this creature enters, you draw X cards and you lose X life, where X is the number of Vampires you control.

Forerunner of the Legion

When this creature enters, you may search your library for a Vampire card, reveal it, then shuffle and put that card on top.
Whenever another Vampire you control enters, target creature gets +1/+1 until end of turn.