Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Vampire of the Dire Moon

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.)

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Sign in Blood

Target player draws two cards and loses 2 life.

Swamp

Sorin, Imperious Bloodlord

+1: Target creature you control gains deathtouch and lifelink until end of turn. If it's a Vampire, put a +1/+1 counter on it.
+1: You may sacrifice a Vampire. When you do, Sorin, Imperious Bloodlord deals 3 damage to any target and you gain 3 life.
−3: You may put a Vampire creature card from your hand onto the battlefield.

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Gifted Aetherborn

Dusk Legion Zealot

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