Gix, Yawgmoth Praetor

Whenever a creature deals combat damage to one of your opponents, its controller may pay 1 life. If they do, they draw a card.
{4}{B}{B}{B}, Discard X cards: Exile the top X cards of target opponent's library. You may play lands and cast spells from among cards exiled this way without paying their mana costs.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Asphyxiate

Dauthi Trapper

{T}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Horn of Greed

Whenever a player plays a land, that player draws a card.

Fain, the Broker

{T}, Sacrifice a creature: Put two +1/+1 counters on target creature.
{T}, Remove a counter from a creature you control: Create a Treasure token.
{T}, Sacrifice an artifact: Create a 2/1 white and black Inkling creature token with flying.
{3}{B}: Untap Fain, the Broker.

Maralen of the Mornsong

Players can't draw cards.
At the beginning of each player's draw step, that player loses 3 life, searches their library for a card, puts it into their hand, then shuffles.

Nocturnal Hunger

Gift a Food (You may promise an opponent a gift as you cast this spell. If you do, they create a Food token before its other effects. It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Destroy target creature. If the gift wasn't promised, you lose 2 life.

Bog Witch

Moment of Defiance

Target creature gets +2/+1 and gains lifelink until end of turn.
Draw a card.

Breach

Target creature gets +2/+0 and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Temple Bell

Dimir Machinations

Look at the top three cards of target player's library. Exile any number of those cards, then put the rest back in any order.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Herald of Torment

Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.

Maggot Therapy

Flash
Enchant creature
Enchanted creature gets +2/-2.

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Butcher's Glee

Target creature gets +3/+0 and gains lifelink until end of turn. Regenerate it. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Blanket of Night

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

Dirge of Dread

All creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)
Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)
When you cycle Dirge of Dread, you may have target creature gain fear until end of turn.

Virtus's Maneuver

For each player, choose friend or foe. Each friend returns a creature card from their graveyard to their hand. Each foe sacrifices a creature of their choice.

Atrocious Experiment

Target player mills two cards, draws two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Boon of Emrakul

Enchant creature
Enchanted creature gets +3/-3.

Assassinate

Victory Chimes

Untap Victory Chimes during each other player's untap step.
{T}: A player of your choice adds {C}.

Aspect of Gorgon

Enchant creature
Enchanted creature gets +1/+3 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy it.)

Grisly Transformation

Enchant creature
When Grisly Transformation enters, draw a card.
Enchanted creature has intimidate. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Endbringer's Revel

{4}: Return target creature card from a graveyard to its owner's hand. Any player may activate this ability but only as a sorcery.

Chittering Rats

When Chittering Rats enters, target opponent puts a card from their hand on top of their library.

Pain's Reward

Each player may bid life. You start the bidding with a bid of any number. In turn order, each player may top the high bid. The bidding ends if the high bid stands. The high bidder loses life equal to the high bid and draws four cards.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Blood Pact

Target player draws two cards and loses 2 life.

Pendant of Prosperity

Pendant of Prosperity enters under the control of an opponent of your choice.
{2}, {T}: Draw a card, then you may put a land card from your hand onto the battlefield. Pendant of Prosperity's owner draws a card, then that player may put a land card from their hand onto the battlefield.

Minion's Return

Flash
Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Ghoulish Impetus

Enchant creature
Enchanted creature gets +1/+1, has deathtouch, and is goaded.
When enchanted creature dies, return Ghoulish Impetus to the battlefield at the beginning of the next end step.

Blood Vassal

Crowded Crypt

{T}: Add {B}.
Whenever a creature you control dies, put a corpse counter on Crowded Crypt.
{4}{B}{B}, {T}, Sacrifice Crowded Crypt: Create a 2/2 black Zombie creature token with decayed for each corpse counter on Crowded Crypt. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Dauthi Embrace

{B}{B}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Consumed by Greed

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Target opponent sacrifices a creature with the greatest power among creatures they control. If the gift was promised, return target creature card from your graveyard to your hand.