Pestilent Syphoner

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Grinning Demon

At the beginning of your upkeep, you lose 2 life.
Morph {2}{B}{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.)

Master of the Feast

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

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Drifter il-Dal

Shadow (This creature can block or be blocked by only creatures with shadow.)
At the beginning of your upkeep, sacrifice Drifter il-Dal unless you pay {U}.

Spindrift Drake

Flying
At the beginning of your upkeep, sacrifice Spindrift Drake unless you pay {U}.

Illusory Demon

Flying
When you cast a spell, sacrifice Illusory Demon.

Abyssal Persecutor

Flying, trample
You can't win the game and your opponents can't lose the game.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Demonic Taskmaster

Flying
At the beginning of your upkeep, sacrifice a creature other than Demonic Taskmaster.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Stenchskipper

Flying
At the beginning of the end step, if you control no Goblins, sacrifice Stenchskipper.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach Bloodthirsty Blade to target creature an opponent controls. Activate only as a sorcery.

Dimir Signet

Fog Elemental

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Fog Elemental attacks or blocks, sacrifice it at end of combat.

Wretched Anurid

Whenever another creature enters, you lose 1 life.

Flesh Reaver

Whenever Flesh Reaver deals damage to a creature or opponent, Flesh Reaver deals that much damage to you.

Voidwing Hybrid

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When you proliferate, return Voidwing Hybrid from your graveyard to your hand.

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.

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Rust Elemental

Flying
At the beginning of your upkeep, sacrifice an artifact other than Rust Elemental. If you can't, tap Rust Elemental and you lose 4 life.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Drinker of Sorrow

Drinker of Sorrow can't block.
Whenever Drinker of Sorrow deals combat damage, sacrifice a permanent.

Jon Irenicus, Shattered One

At the beginning of your end step, target opponent gains control of up to one target creature you control. Put two +1/+1 counters on it and tap it. It's goaded for the rest of the game and it gains "This creature can't be sacrificed." (It attacks each combat if able and attacks a player other than you if able.)
Whenever a creature you own but don't control attacks, you draw a card.

Runaway Carriage

Trample
When Runaway Carriage attacks or blocks, sacrifice it at end of combat.

Circling Vultures

Flying
You may discard Circling Vultures any time you could cast an instant.
At the beginning of your upkeep, sacrifice Circling Vultures unless you exile the top creature card of your graveyard.

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Thought Devourer

Flying
Your maximum hand size is reduced by four.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Vraska's Fall

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.

Go for the Throat

Fledgling Djinn

Flying
At the beginning of your upkeep, Fledgling Djinn deals 1 damage to you.

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Necrogen Communion

Enchant creature you control
Enchanted creature has toxic 2. (Players dealt combat damage by it also get two poison counters.)
When enchanted creature dies, return that card to the battlefield under your control.

Thought Eater

Flying
Your maximum hand size is reduced by three.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Molting Harpy

Flying
At the beginning of your upkeep, sacrifice Molting Harpy unless you pay {2}.

Sol Ring

Priest of the Blood Rite

When Priest of the Blood Rite enters, create a 5/5 black Demon creature token with flying.
At the beginning of your upkeep, you lose 2 life.

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Negate

Counterspell

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Psychic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you scry 2.

Throne of Death

At the beginning of your upkeep, mill a card.
{2}{B}, {T}, Exile a creature card from your graveyard: Draw a card.

Egon, God of Death

Deathtouch
At the beginning of your upkeep, exile two cards from your graveyard. If you can't, sacrifice Egon and draw a card.

Egon, God of Death // Throne of Death

Arcane Signet

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

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Infernal Grasp

Destroy target creature. You lose 2 life.

Thought Nibbler

Flying
Your maximum hand size is reduced by two.

Mind Stone

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

Ebon Drake

Flying
Whenever a player casts a spell, you lose 1 life.

Pitiless Horde

At the beginning of your upkeep, you lose 2 life.
Dash {2}{B}{B} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Parasitic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, its controller loses 2 life and you gain 2 life.

Archfiend of the Dross

Flying
Archfiend of the Dross enters with four oil counters on it.
At the beginning of your upkeep, remove an oil counter from Archfiend of the Dross. Then if it has no oil counters on it, you lose the game.
Whenever a creature an opponent controls dies, its controller loses 2 life.