Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Vampire Spawn

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

Vampire Neonate

{2}, {T}: Each opponent loses 1 life and you gain 1 life.

Crossway Troublemakers

Attacking Vampires you control have deathtouch and lifelink. (Any amount of damage they deal to a creature is enough to destroy it. Damage dealt by those creatures also causes their controller to gain that much life.)
Whenever a Vampire you control dies, you may pay 2 life. If you do, draw a card.

Untamed Hunger

Enchant creature
Enchanted creature gets +2/+1 and has menace. (It can't be blocked except by two or more creatures.)

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 Interloper

Bloodtithe Collector

Flying
When this creature enters, if an opponent lost life this turn, each opponent discards a card.

Uncharted Haven

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Moment of Craving

Target creature gets -2/-2 until end of turn. You gain 2 life.

Swamp

Hero's Downfall

Highborn Vampire

Vengeful Bloodwitch

Whenever this creature or another creature you control dies, target opponent loses 1 life and you gain 1 life.