Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Sol Ring

Hemlock Vial

When Hemlock Vial enters, you draw a card and you lose 1 life.
{B}, {T}, Sacrifice Hemlock Vial: Each equipped creature and Equipment you control gains deathtouch until end of turn.

Lost Legion

When Lost Legion enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Daggerdrome Imp

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Fountainport

{T}: Add {C}.
{2}, {T}, Sacrifice a token: Draw a card.
{3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token.
{4}, {T}: Create a Treasure token.

Essence Harvest

Target player loses X life and you gain X life, where X is the greatest power among creatures you control.

Child of Night

Starlit Soothsayer

Flying
At the beginning of your end step, if you gained or lost life this turn, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Grasp of Darkness

Target creature gets -4/-4 until end of turn.

Abattoir Ghoul

First strike
Whenever a creature dealt damage by Abattoir Ghoul this turn dies, you gain life equal to that creature's toughness.

Soulcage Fiend

When Soulcage Fiend dies, each player loses 3 life.

Diresight

Surveil 2, then draw two cards. You lose 2 life. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Cruel Sadist

{B}, {T}, Pay 1 life: Put a +1/+1 counter on Cruel Sadist.
{2}{B}, {T}, Remove X +1/+1 counters from Cruel Sadist: It deals X damage to target creature.

Malakir Familiar

Flying, deathtouch
Whenever you gain life, Malakir Familiar gets +1/+1 until end of turn.

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature.

Thornplate Intimidator

Offspring {3} (You may pay an additional {3} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
When this creature enters, target opponent loses 3 life unless they sacrifice a nonland permanent or discard a card.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Murder

Last Kiss

Last Kiss deals 2 damage to target creature and you gain 2 life.

Vampire Spawn

When Vampire Spawn enters, each opponent loses 2 life and you gain 2 life.

Mark of the Vampire

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.

Swamp

Royal Assassin

Bitter Revelation

Look at the top four cards of your library. Put two of them into your hand and the rest into your graveyard. You lose 2 life.

Nuclear Fallout

Each creature gets twice -X/-X until end of turn. Each player gets X rad counters.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Pulse Tracker

Whenever Pulse Tracker attacks, each opponent loses 1 life.

Daggerfang Duo

Deathtouch
When Daggerfang Duo enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Thought-Stalker Warlock

Menace (This creature can't be blocked except by two or more creatures.)
When Thought-Stalker Warlock enters, choose target opponent. If they lost life this turn, they reveal their hand, you choose a nonland card from it, and they discard that card. Otherwise, they discard a card.

Sinister Monolith

At the beginning of combat on your turn, each opponent loses 1 life and you gain 1 life.
{T}, Pay 2 life, Sacrifice Sinister Monolith: Draw two cards. Activate only as a sorcery.

Huskburster Swarm

This spell costs {1} less to cast for each creature card you own in exile and in your graveyard.
Menace, deathtouch

Fell

Driver of the Dead

When Driver of the Dead dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Cremate

Exile target card from a graveyard.
Draw a card.

Soul-Guide Lantern

When Soul-Guide Lantern enters, exile target card from a graveyard.
{T}, Sacrifice Soul-Guide Lantern: Exile each opponent's graveyard.
{1}, {T}, Sacrifice Soul-Guide Lantern: Draw a card.

Glidedive Duo

Flying
When Glidedive Duo enters, each opponent loses 2 life and you gain 2 life.

Agate-Blade Assassin

Whenever Agate-Blade Assassin attacks, defending player loses 1 life and you gain 1 life.

Savor

Target creature gets -2/-2 until end of turn. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Wall of Limbs

Defender (This creature can't attack.)
Whenever you gain life, put a +1/+1 counter on Wall of Limbs.
{5}{B}{B}, Sacrifice Wall of Limbs: Target player loses X life, where X is Wall of Limbs's power.

Sidisi's Pet

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Morph {1}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Dutiful Attendant

When Dutiful Attendant dies, return another target creature card from your graveyard to your hand.

Slum Reaper

When Slum Reaper enters, each player sacrifices a creature.

Ravine Raider

Menace (This creature can't be blocked except by two or more creatures.)
{1}{B}: Ravine Raider gets +1/+1 until end of turn.

Mephitic Vapors

All creatures get -1/-1 until end of turn.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Phantom Blade

When Phantom Blade enters, attach it to up to one target creature you control. Destroy up to one other target creature.
Equipped creature gets +1/+1 and has menace. (It can't be blocked except by two or more creatures.)
Equip {2}

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

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.

Triumph of Cruelty

At the beginning of your upkeep, target opponent discards a card if you control the creature with the greatest power or tied for the greatest power.

Hazel's Nocturne

Return up to two target creature cards from your graveyard to your hand. Each opponent loses 2 life and you gain 2 life.

Corpse Traders

{2}{B}, Sacrifice a creature: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.

Skinrender

When Skinrender enters, put three -1/-1 counters on target creature.

Gravedigger

When Gravedigger enters, you may return target creature card from your graveyard to your hand.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Unscrupulous Agent

When Unscrupulous Agent enters, target opponent exiles a card from their hand.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Ruthless Negotiation

Target opponent exiles a card from their hand. If this spell was cast from a graveyard, draw a card.
Flashback {4}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Rising Miasma

All creatures get -2/-2 until end of turn.
Awaken 3—{5}{B}{B} (If you cast this spell for {5}{B}{B}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)