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.)

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.

Ghost Vacuum

{T}: Exile target card from a graveyard.
{6}, {T}, Sacrifice this artifact: Put each creature card exiled with this artifact onto the battlefield under your control with a flying counter on it. Each of them is a 1/1 Spirit in addition to its other types. Activate only as a sorcery.

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 left the battlefield under your control this turn.

Ritual Chamber

When you unlock this door, create a 6/6 black Demon creature token with flying.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life and you gain 2 life. Otherwise, you lose 2 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Unholy Annex // Ritual Chamber

Thoughtseize

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

Bloodthirsty Conqueror

Flying, deathtouch
Whenever an opponent loses life, you gain that much life. (Damage causes loss of life.)

Preacher of the Schism

Deathtouch
Whenever this creature attacks the player with the most life or tied for most life, create a 1/1 white Vampire creature token with lifelink.
Whenever this creature attacks while you have the most life or are tied for most life, you draw a card and you lose 1 life.

Mutavault

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

Queen's Bay Paladin

Whenever this creature enters or attacks, return up to one target Vampire card from your graveyard to the battlefield with a finality counter on it. You lose life equal to its mana value. (If a creature with a finality counter on it would die, exile it instead.)

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Go for the Throat

Qarsi Revenant

Flying, deathtouch, lifelink
Renew — {2}{B}, Exile this card from your graveyard: Put a flying counter, a deathtouch counter, and a lifelink counter on target creature. Activate only as a sorcery.

Duress

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

Withering Torment

Destroy target creature or enchantment. 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.)

Gifted Aetherborn

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Swamp

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard this card: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Castle Locthwain

This land enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.