Duskwielder

Boast — {1}: Target opponent loses 1 life and you gain 1 life. (Activate only if this creature attacked this turn and only once each turn.)

Necrotic Fumes

As an additional cost to cast this spell, exile a creature you control.
Exile target creature or planeswalker.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Poet's Quill

When Poet's Quill enters, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)
Equipped creature gets +1/+1 and has lifelink.
Equip {1}{B}

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Pest Summoning

Create two 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life."

Bloodchief's Thirst

Kicker {2}{B} (You may pay an additional {2}{B} as you cast this spell.)
Destroy target creature or planeswalker with mana value 2 or less. If this spell was kicked, instead destroy target creature or planeswalker.

Duress

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

Blood Fountain

When Blood Fountain enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{3}{B}, {T}, Sacrifice Blood Fountain: Return up to two target creature cards from your graveyard to your hand.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Gluttonous Guest

When Gluttonous Guest enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Blood token, you gain 1 life.

Introduction to Prophecy

Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Falkenrath Forebear

Flying
Falkenrath Forebear can't block.
Whenever Falkenrath Forebear deals combat damage to a player, create a Blood token.
{B}, Sacrifice two Blood tokens: Return Falkenrath Forebear from your graveyard to the battlefield.

Mind Drain

Target opponent discards two cards, mills a card, and loses 1 life. You gain 1 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Bloodsoaked Reveler

At the beginning of your end step, if you gained life this turn, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{4}{B}: Each opponent loses 2 life and you gain 2 life.

Restless Bloodseeker

At the beginning of your end step, if you gained life this turn, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
Sacrifice two Blood tokens: Transform Restless Bloodseeker. Activate only as a sorcery.

Restless Bloodseeker // Bloodsoaked Reveler

Dread Fugue

Cleave {2}{B} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Target player reveals their hand. You choose a nonland card from it [with mana value 2 or less]. That player discards that card.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Swamp

Nullpriest of Oblivion

Kicker {3}{B} (You may pay an additional {3}{B} as you cast this spell.)
Lifelink
Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, if it was kicked, return target creature card from your graveyard to the battlefield.