Severed Strands

As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness. Destroy target creature an opponent controls.

Stromkirk Bloodthief

At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on target Vampire you control.

Vampire Spawn

When this creature enters, each opponent loses 2 life and you gain 2 life.

Queen's Bay Soldier

Gravedigger

When this creature enters, you may return target creature card from your graveyard to your hand.

Murder

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature.

Severed Legion

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Swamp

Fetid Imp

Flying
{B}: This creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)