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.

Mind Stone

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

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Liliana, Defiant Necromancer

+2: Each player discards a card.
−X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.
−8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Liliana, Heretical Healer

Lifelink
Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

Liliana, Heretical Healer // Liliana, Defiant Necromancer

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Burnished Hart

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

Shred Memory

Exile up to four target cards from a single graveyard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Thran Dynamo

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

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.

Gilded Lotus

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Damnation

Destroy all creatures. They can't be regenerated.

Arcane Signet

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

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

Bone Miser

Whenever you discard a creature card, create a 2/2 black Zombie creature token.
Whenever you discard a land card, add {B}{B}.
Whenever you discard a noncreature, nonland card, draw a card.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Delirium Skeins

Mire in Misery

Each opponent sacrifices a creature or enchantment of their choice.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Words of Waste

{1}: The next time you would draw a card this turn, each opponent discards a card instead.

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Dark Confidant

At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

No Mercy

Whenever a creature deals damage to you, destroy it.

Lightning Greaves

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

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}.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Cunning Lethemancer

At the beginning of your upkeep, each player discards a card.

Demonic Tutor

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

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Jet Medallion

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

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Dark Ritual

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Oppression

Whenever a player casts a spell, that player discards a card.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Fell Specter

Flying
When Fell Specter enters, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.

Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Necrogen Mists

At the beginning of each player's upkeep, that player discards a card.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Mind Rake

Target player discards two cards.
Overload {1}{B} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Liliana, Waker of the Dead

+1: Each player discards a card. Each opponent who can't loses 3 life.
−3: Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard.
−7: You get an emblem with "At the beginning of combat on your turn, put target creature card from a graveyard onto the battlefield under your control. It gains haste."

Anvil of Bogardan

Players have no maximum hand size.
At the beginning of each player's draw step, that player draws an additional card, then discards a card.

Karn, Scion of Urza

+1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it.
−1: Put a card you own with a silver counter on it from exile into your hand.
−2: Create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Sol Ring

Rankle, Master of Pranks

Flying, haste
Whenever Rankle, Master of Pranks deals combat damage to a player, choose any number —
• Each player discards a card.
• Each player loses 1 life and draws a card.
• Each player sacrifices a creature of their choice.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Thought Vessel

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

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Arterial Flow

Each opponent discards two cards. If you control a Vampire, each opponent loses 2 life and you gain 2 life.

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Solemn Simulacrum

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

Night's Whisper

Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice Bag of Holding: Return all cards exiled with Bag of Holding to their owner's hand.

Tinybones, Trinket Thief

At the beginning of each end step, if an opponent discarded a card this turn, you draw a card and you lose 1 life.
{4}{B}{B}: Each opponent with no cards in hand loses 10 life.