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 of their choice.

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.

Flesh Reaver

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

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.

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.

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.

Wrong Turn

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

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.

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.

Ebon Drake

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

Demonic Taskmaster

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

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.

Abyssal Persecutor

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

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.

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.