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.

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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Demonic Taskmaster

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

Abyssal Persecutor

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

Crawlspace

No more than two creatures can attack you each combat.

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.

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.)

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Aetherize

Return all attacking creatures to their owner's hand.

Cursed Totem

Activated abilities of creatures can't be activated.

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.

Arcane Signet

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

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Lord of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than Lord of the Pit. If you can't, Lord of the Pit deals 7 damage to you.

Phyrexian Soulgorger

Cumulative upkeep—Sacrifice a creature. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Ebon Drake

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

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Dimir Signet

Flesh Reaver

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

Alexi's Cloak

Flash
Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)

Footsteps of the Goryo

Return target creature card from your graveyard to the battlefield. Sacrifice that creature at the beginning of the next end step.

Damnation

Destroy all creatures. They can't be regenerated.

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Drinker of Sorrow

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

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.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

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.

Grid Monitor

Wretched Anurid

Whenever another creature enters, you lose 1 life.

Jet Medallion

Black spells you cast cost {1} less to cast.

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.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Phyrexian Negator

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

Murder

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Sol Ring

Propaganda

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

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.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents of their choice.

Yukora, the Prisoner

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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.

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.

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.)

Commander's Sphere

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

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Infernal Grasp

Destroy target creature. You lose 2 life.

Thought Eater

Flying
Your maximum hand size is reduced by three.

Phantasmal Image

You may have Phantasmal Image enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

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.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Skeletal Scrying

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and you lose X life.

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.)

Dauthi Trapper

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