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.

Abyssal Persecutor

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

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.

Asmodeus the Archfiend

Binding Contract — If you would draw a card, exile the top card of your library face down instead.
{B}{B}{B}: Draw seven cards.
{B}: Return all cards exiled with Asmodeus the Archfiend to their owner's hand and you lose that much life.

Demonic Taskmaster

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

Derelor

Black spells you cast cost {B} more to cast.

Desecration Elemental

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever a player casts a spell, sacrifice a creature.

Ebonblade Reaper

Whenever Ebonblade Reaper attacks, you lose half your life, rounded up.
Whenever Ebonblade Reaper deals combat damage to a player, that player loses half their life, rounded up.
Morph {3}{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.)

Evil Eye of Orms-by-Gore

Non-Eye creatures you control can't attack.
Evil Eye of Orms-by-Gore can't be blocked except by Walls.

Evil Eye of Urborg

Non-Eye creatures you control can't attack.
Whenever Evil Eye of Urborg becomes blocked by a creature, destroy that creature.

Flesh Reaver

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

Gisa, Glorious Resurrector

If a creature an opponent controls would die, exile it instead.
At the beginning of your upkeep, put all creature cards exiled with Gisa, Glorious Resurrector onto the battlefield under your control. They gain decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Grid Monitor

Liege of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than Liege of the Pit. If you can't, Liege of the Pit deals 7 damage to you.
Morph {B}{B}{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.)

Phyrexian Vatmother

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, you get a poison counter.

Plague Reaver

At the beginning of your end step, sacrifice each other creature you control.
Discard two cards, Sacrifice Plague Reaver: Choose target opponent. Return Plague Reaver to the battlefield under that player's control at the beginning of their next upkeep.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

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.

Steel Golem

Taniwha

Trample
Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)
At the beginning of your upkeep, all lands you control phase out. (They phase in before you untap during your next untap step.)

Yukora, the Prisoner

When Yukora, the Prisoner leaves the battlefield, sacrifice all non-Ogre creatures you control.

Ebon Drake

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

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.)

Gutwrencher Oni

Trample
At the beginning of your upkeep, discard a card if you don't control an Ogre.

Painwracker Oni

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
At the beginning of your upkeep, sacrifice a creature if you don't control an Ogre.

Morkrut Necropod

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Morkrut Necropod attacks or blocks, sacrifice another creature or land.

Sleeper Agent

When Sleeper Agent enters, target opponent gains control of it.
At the beginning of your upkeep, Sleeper Agent deals 2 damage to you.

Endless Whispers

Each creature has "When this creature dies, choose target opponent. That player puts this card from its owner's graveyard onto the battlefield under their control at the beginning of the next end step."

Wretched Anurid

Whenever another creature enters, you lose 1 life.

Coveted Falcon

Flying
Whenever Coveted Falcon attacks, gain control of target permanent you own but don't control.
Disguise {1}{U}
When Coveted Falcon is turned face up, target opponent gains control of any number of target permanents you control. Draw a card for each one they gained control of this way.

Modify Memory

Exchange control of two target creatures controlled by different players. If you control neither creature, draw three cards.

Thought Devourer

Flying
Your maximum hand size is reduced by four.

Exchange of Words

When Exchange of Words enters, choose two target creatures. For as long as Exchange of Words remains on the battlefield, exchange the text boxes of those creatures.

Chromeshell Crab

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Legerdemain

Exchange control of target artifact or creature and another target permanent that shares one of those types with it. (This effect lasts indefinitely.)

Shifting Grift

Spree (Choose one or more additional costs.)
+ {2} — Exchange control of two target creatures.
+ {1} — Exchange control of two target artifacts.
+ {1} — Exchange control of two target enchantments.

Spawnbroker

When Spawnbroker enters, you may exchange control of target creature you control and target creature with power less than or equal to that creature's power an opponent controls.

Wrong Turn

Target opponent gains control of target creature. (If an attacking or blocking creature changes controllers, it's removed from combat.)

Puca's Mischief

At the beginning of your upkeep, you may exchange control of target nonland permanent you control and target nonland permanent an opponent controls with equal or lesser mana value.

Djinn of Infinite Deceits

Flying
{T}: Exchange control of two target nonlegendary creatures. You can't activate this ability during combat.

Jinxed Idol

At the beginning of your upkeep, Jinxed Idol deals 2 damage to you.
Sacrifice a creature: Target opponent gains control of Jinxed Idol.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Redirect

You may choose new targets for target spell.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Collective Restraint

Domain — Creatures can't attack you unless their controller pays {X} for each creature they control that's attacking you, where X is the number of basic land types among lands you control.

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

Greater Harvester

At the beginning of your upkeep, sacrifice a permanent.
Whenever Greater Harvester deals combat damage to a player, that player sacrifices two permanents.

Phyrexian Negator

Trample
Whenever Phyrexian Negator is dealt damage, sacrifice that many permanents.

Thought Eater

Flying
Your maximum hand size is reduced by three.

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.

Abhorrent Overlord

Flying
When Abhorrent Overlord enters, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

Switcheroo

Exchange control of two target creatures.

Crawlspace

No more than two creatures can attack you each combat.

Despotic Scepter

{T}: Destroy target permanent you own. It can't be regenerated.

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Sol Ring

Arcane Signet

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

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.

Demonic Pact

At the beginning of your upkeep, choose one that hasn't been chosen —
• Demonic Pact deals 4 damage to any target and you gain 4 life.
• Target opponent discards two cards.
• Draw two cards.
• You lose the game.