Thassa's Oracle

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Breathstealer's Crypt

If a player would draw a card, instead they draw a card and reveal it. If it's a creature card, that player discards it unless they pay 3 life.

Famine

Famine deals 3 damage to each creature and each player.

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Zombie Infestation

Discard two cards: Create a 2/2 black Zombie creature token.

Curse of Wizardry

As Curse of Wizardry enters the battlefield, choose a color.
Whenever a player casts a spell of the chosen color, that player loses 1 life.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Dauthi Embrace

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

Reliquary Tower

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

Marchesa's Decree

When Marchesa's Decree enters the battlefield, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Loyal Subordinate

Menace
Lieutenant — At the beginning of combat on your turn, if you control your commander, each opponent loses 3 life.

Syphon Life

Target player loses 2 life and you gain 2 life.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Temple Bell

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Court of Ambition

When Court of Ambition enters the battlefield, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Thought Vessel

Jwari Ruins

Jwari Ruins enters the battlefield tapped.
{T}: Add {U}.

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Choked Estuary

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.
{T}: Add {U} or {B}.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Dimir Aqueduct

Dimir Aqueduct enters the battlefield tapped.
When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis, the Hate-Twisted deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Deadly Tempest

Destroy all creatures. Each player loses life equal to the number of creatures they controlled that were destroyed this way.

Duskmantle Seer

Flying
At the beginning of your upkeep, each player reveals the top card of their library, loses life equal to that card's mana value, then puts it into their hand.

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Ancient Tomb

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

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.

Blood Pact

Target player draws two cards and loses 2 life.

Clutch of the Undercity

Return target permanent to its owner's hand. Its controller loses 3 life.
Transmute {1}{U}{B} ({1}{U}{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.)

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Jace's Archivist

{U}, {T}: Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Ghostly Pilferer

Whenever Ghostly Pilferer becomes untapped, you may pay {2}. If you do, draw a card.
Whenever an opponent casts a spell from anywhere other than their hand, draw a card.
Discard a card: Ghostly Pilferer can't be blocked this turn.

Jinxed Choker

At the beginning of your end step, target opponent gains control of Jinxed Choker and puts a charge counter on it.
At the beginning of your upkeep, Jinxed Choker deals damage to you equal to the number of charge counters on it.
{3}: Put a charge counter on Jinxed Choker or remove one from it.

Faerie Tauntings

Whenever you cast a spell during an opponent's turn, you may have each opponent lose 1 life.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Undermine

Counter target spell. Its controller loses 3 life.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Damnable Pact

Target player draws X cards and loses X life.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Howling Banshee

Flying
When Howling Banshee enters the battlefield, each player loses 3 life.

Urza's Guilt

Each player draws two cards, then discards three cards, then loses 4 life.

Exsanguinate

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

Countersquall

Counter target noncreature spell. Its controller loses 2 life.

Silundi Isle

Silundi Isle enters the battlefield tapped.
{T}: Add {U}.

Silundi Vision

Look at the top six cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Silundi Vision // Silundi Isle

Twilight Prophet

Flying
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, if you have the city's blessing, reveal the top card of your library and put it into your hand. Each opponent loses X life and you gain X life, where X is that card's mana value.

Darkwater Catacombs

Viseling

At the beginning of each opponent's upkeep, Viseling deals X damage to that player, where X is the number of cards in their hand minus 4.

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Ankh of Mishra

Whenever a land enters the battlefield, Ankh of Mishra deals 2 damage to that land's controller.

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Demonic Consultation

Choose a card name. Exile the top six cards of your library, then reveal cards from the top of your library until you reveal a card with the chosen name. Put that card into your hand and exile all other cards revealed this way.

Shelldock Isle

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Shelldock Isle enters the battlefield tapped.
{T}: Add {U}.
{U}, {T}: You may play the exiled card without paying its mana cost if a library has twenty or fewer cards in it.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Command Tower

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

Barbed Wire

At the beginning of each player's upkeep, Barbed Wire deals 1 damage to that player.
{2}: Prevent the next 1 damage that would be dealt by Barbed Wire this turn.

Seat of the Synod

Vile Consumption

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay 1 life."

Exotic Orchard

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

Vault of Whispers

Crypt Rats

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Counterspell

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.