Keeper of Secrets

First strike, haste
Symphony of Pain — Whenever you cast a spell from anywhere other than your hand, Keeper of Secrets deals damage equal to that spell's mana value to target opponent.

Trenzalore Clocktower

{T}: Add {U}. Put a time counter on Trenzalore Clocktower.
{1}{U}, {T}, Remove twelve time counters from Trenzalore Clocktower and exile it: Shuffle your graveyard and hand into your library, then draw seven cards. Activate only if you control a Time Lord.

Hotel of Fears

At the beginning of your upkeep, exile the top card of your library. You lose life equal to its mana value. You may play that card this turn.
Praise Him — Whenever chaos ensues, choose a color. Put X +1/+1 counters on target creature you control, where X is your devotion to that color. Then sacrifice another creature. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Singing Towers of Darillium

Each nonland card in your hand without foretell has foretell. Its foretell cost is equal to its mana cost reduced by {2}. (During your turn, you may pay {2} and exile it from your hand face down. Cast it on a later turn for its foretell cost.)
Whenever chaos ensues, you may cast a foretold card you own from exile without paying its mana cost this turn.

Two Streams Facility

Whenever you planeswalk to Two Streams Facility and at the beginning of the first upkeep of the game, each player chooses green anchor or red waterfall.
Each player who last chose green anchor may play an additional land during each of their turns.
Creatures controlled by players who last chose red waterfall get +2/+0 and have haste.
Whenever chaos ensues, each player who last chose green anchor chooses red waterfall, and vice versa.

TARDIS Bay

The first spell you cast during each of your turns with mana value 2 or greater has cascade. (When you cast that spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
When chaos ensues, gain control of target artifact. Then planeswalk.

The Moonbase

Low Gravity — All creatures have "{2}: This creature gains flying until end of turn. Activate only as a sorcery."
Whenever chaos ensues, for each opponent, choose up to one target creature card in that player's graveyard. Put those cards onto the battlefield face down under your control. They're 2/2 Cyberman artifact creatures.

Dark Apostle

Gift of Chaos — {3}, {T}: The next noncreature spell you cast this turn has cascade. (When you cast that spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Unleash the Flux

When you encounter Unleash the Flux, each player sacrifices a nonland permanent, then you flip a coin. If you lose the flip, repeat this process. (Then planeswalk away from this phenomenon.)

The Cheetah Planet

When you planeswalk to The Cheetah Planet and at the beginning of your upkeep, put two +1/+1 counters on target non-Cat creature you control. It becomes a Cat in addition to its other types.
Whenever chaos ensues, all Cats gain provoke until end of turn. (Whenever a Cat attacks, its controller may have target creature defending player controls untap and block it if able.)

Return the Past

As long as it's your turn, each instant and sorcery card in your graveyard has flashback. Its flashback cost is equal to its mana cost.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

The War Doctor

Whenever one or more other permanents phase out and whenever one or more other cards are put into exile from anywhere, put a time counter on The War Doctor.
Whenever The War Doctor attacks, it deals damage equal to the number of time counters on it to any target. If a creature dealt damage this way would die this turn, exile it instead.

Passionate Archaeologist

Commander creatures you own have "Whenever you cast a spell from exile, this creature deals damage equal to that spell's mana value to target opponent."

Mondassian Colony Ship

Whenever a creature attacks, it gets +1/+1 until end of turn for each other creature its controller controls that shares a creature type with it.
Whenever chaos ensues, turn target creature face down. It becomes a 2/2 Cyberman artifact creature.

Sundown Pass

Sundown Pass enters the battlefield tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

The Drum, Mining Facility

Whenever you roll the planar die, creatures you control get +1/+1 and gain haste until end of turn.
Whenever chaos ensues, end the turn. (Exile all spells and abilities from the stack. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Guff Rewrites History

For each player, choose target nonenchantment, nonland permanent that player controls. Those permanents' owners shuffle them into their libraries. Each player who controlled one of those permanents exiles cards from the top of their library until they exile a nonland card, then puts the rest on the bottom of their library in a random order. Each player may cast the nonland card they exiled without paying its mana cost.

Plargg and Nassari

At the beginning of your upkeep, each player exiles cards from the top of their library until they exile a nonland card. An opponent chooses a nonland card exiled this way. You may cast up to two spells from among the other cards exiled this way without paying their mana costs.

The Pyramid of Mars

When you planeswalk to The Pyramid of Mars and at beginning of your upkeep, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Whenever chaos ensues, return target creature card from your graveyard to the battlefield.

River Song's Diary

Imprint — Whenever a player casts an instant or sorcery spell from their hand, exile it instead of putting it into a graveyard as it resolves.
At the beginning of your upkeep, if there are four or more cards exiled with River Song's Diary, choose one of them at random. You may cast it without paying its mana cost.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Myriad Landscape

Myriad Landscape enters the battlefield 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.

Sol Ring

The Cave of Skulls

Each creature card in your graveyard has scavenge. The scavenge cost is equal to its mana cost. (Exile a creature card from your graveyard and pay its mana cost: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Whenever chaos ensues, create two 1/1 white Warrior creature tokens.

Fixed Point in Time

When you encounter Fixed Point in Time, until your next turn, if a player would planeswalk as a result of rolling the planar die, chaos ensues instead. (Then planeswalk away from this phenomenon.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Flaming Tyrannosaurus

Menace
Paradox — Whenever you cast a spell from anywhere other than your hand, Flaming Tyrannosaurus deals 3 damage to any target. Then put a +1/+1 counter on Flaming Tyrannosaurus.
When Flaming Tyrannosaurus dies, it deals damage equal to its power to each opponent.

City of the Daleks

Whenever you attack, target opponent loses X life, where X is the number of artifacts you control.
Whenever chaos ensues, for each opponent, you create a 3/3 black Dalek artifact creature token with menace that attacks that opponent this turn if able. Those tokens gain haste. Sacrifice them at the beginning of the next end step.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Pompeii

When you planeswalk to Pompeii and at the beginning of your upkeep, put an eruption counter on it.
Whenever you roll a blank on the planar die, scry 2. Then put an eruption counter on Pompeii.
When chaos ensues, Pompeii deals damage to each creature and each player equal to the number of eruption counters on Pompeii. Each player sacrifices a land. Then planeswalk.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Sunbaked Canyon

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Sunbaked Canyon: Draw a card.

Mechanized Production

Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Lake Silencio

Still Point in Time — All spells have split second. (As long as a spell with split second is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Whenever chaos ensues, Lake Silencio deals 6 damage to target creature an opponent controls. If a creature dealt damage this way would die this turn, exile it instead.

The Matrix of Time

When you planeswalk to The Matrix of Time, each player exiles the top card of their library.
During your turn, you may play lands and cast spells from among cards exiled with The Matrix of Time.
Whenever you play a land or cast a spell from among cards exiled with The Matrix of Time, that card's owner loses 3 life and exiles the top card of their library.
Whenever chaos ensues, create two Treasure tokens.

Mizzix, Replica Rider

Flying
Whenever you cast a spell from anywhere other than your hand, you may pay {1}{U/R}. If you do, copy that spell and you may choose new targets for the copy. If the copy is a permanent spell, it gains haste and "At the beginning of your end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.)

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Ethersworn Sphinx

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card with lesser mana value. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Inevitable Betrayal

Suspend 3—{1}{U}{U} (Rather than cast this card from your hand, pay {1}{U}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Nalfeshnee

Flying
Whenever you cast a spell from exile, copy it. You may choose new targets for the copy. If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.)

Ood Sphere

Song of the Ood — Noncreature spells have convoke. (A player's creatures can help cast those spells. Each creature they tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
Red-Eye — Whenever chaos ensues, for each opponent, goad up to one target creature that opponent controls. Until your next turn, those creatures can't become tapped unless they're being declared as attackers.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Volcanic Torrent

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Volcanic Torrent deals X damage to each creature and planeswalker your opponents control, where X is the number of spells you've cast this turn.

North Pole Research Base

At the beginning of your upkeep, target opponent draws a card and creates a Treasure token.
Whenever chaos ensues, create a 2/2 white Alien creature token. When you do, tap target nontoken creature an opponent controls. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Talisman of Progress

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

Temple of Triumph

Temple of Triumph enters the battlefield tapped.
When Temple of Triumph enters the battlefield, scry 1.
{T}: Add {R} or {W}.

Stormcage Containment Facility

Each creature card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
Whenever chaos ensues, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Aplan Mortarium

Byzantium Radiation — At the beginning of your upkeep, put an exposure counter on Aplan Mortarium. Then you lose life equal to the number of exposure counters on it.
Whenever chaos ensues, create two 2/2 black Alien Angel artifact creature tokens with first strike, vigilance, and "Whenever an opponent casts a creature spell, this permanent isn't a creature until end of turn."

The Lux Foundation Library

Players have no maximum hand size.
Whenever a creature you control deals combat damage to a player, you may draw a card.
Whenever chaos ensues, put a shadow counter on target creature. (A creature with shadow can block or be blocked by only creatures with shadow.)

Into the Time Vortex

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Stormcarved Coast

Stormcarved Coast enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Reliquary Tower

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

The Twelfth Doctor

The first spell you cast from anywhere other than your hand each turn has demonstrate. (When you cast that spell, you may copy it. If you do, choose an opponent to also copy it. A copy of a permanent spell becomes a token.)
Whenever you copy a spell, put a +1/+1 counter on The Twelfth Doctor.

See the Truth

Look at the top three cards of your library. Put one of those cards into your hand and the rest on the bottom of your library in any order. If this spell was cast from anywhere other than your hand, put each of those cards into your hand instead.

Flamekin Herald

Commander spells you cast have cascade. (Whenever you cast a commander, exile cards from the top of your library until you exile a nonland card with lesser mana value. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Padeem, Consul of Innovation

Artifacts you control have hexproof.
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Teleportation Circle

At the beginning of your end step, exile up to one target artifact or creature you control, then return that card to the battlefield under its owner's control.

The Doctor's Childhood Barn

Creatures enter the battlefield tapped.
Whenever chaos ensues, for each opponent, choose up to one target nonland permanent that opponent controls. Untap those permanents. They phase out. They can't phase in for as long as The Doctor's Childhood Barn remains face up. When a player planeswalks, those permanents phase in.

Temple of Enlightenment

Temple of Enlightenment enters the battlefield tapped.
When Temple of Enlightenment enters the battlefield, scry 1.
{T}: Add {W} or {U}.

Noise Marine

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)
Sonic Blaster — When Noise Marine enters the battlefield, it deals damage equal to the number of spells you've cast this turn to any target.

Extraordinary Journey

When Extraordinary Journey enters the battlefield, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter the battlefield, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Kerblam! Warehouse

Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Whenever chaos ensues, until your next turn, noncreature artifacts you control gain "{T}, Sacrifice this artifact: Flip a coin. If you win the flip, this artifact deals 3 damage to any target."

Boarding Party

Haste
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Baral's Expertise

Return up to three target artifacts and/or creatures to their owners' hands.
You may cast a spell with mana value 4 or less from your hand without paying its mana cost.

Mystic Monastery

Mystic Monastery enters the battlefield tapped.
{T}: Add {U}, {R}, or {W}.

Coal Hill School

Whenever a player casts a historic spell, that player draws a card. (Artifacts, legendaries, and Sagas are historic.)
Whenever chaos ensues, return target historic card from your graveyard to your hand.

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Human-Time Lord Meta-Crisis

When you encounter Human-Time Lord Meta-Crisis, each player chooses one or two creatures they control. Each player creates a token that's a copy of the first creature they chose, except it isn't legendary. Then each player who chose a second creature puts a number of +1/+1 counters on the token they created equal to the power of the second creature they chose. (Then planeswalk away from this phenomenon.)

New New York

At the beginning of combat on your turn, until end of turn, noncreature artifacts you control become 3/3 Vehicles in addition to their other types and gain flying, haste, and crew 1.
Whenever chaos ensues, create a Treasure token and a 2/2 white Alien creature token.

The Golden City of Orazca

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token. Then draw a card if you have the city's blessing.
Whenever chaos ensues, you may put a permanent card from your hand onto the battlefield tapped.

Command Tower

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

Drafna, Founder of Lat-Nam

{1}{U}: Return target artifact you control to its owner's hand.
{3}, {T}: Copy target artifact spell you control. (The copy becomes a token.)

Etherium-Horn Sorcerer

{1}{U}{R}: Return Etherium-Horn Sorcerer to its owner's hand.
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Thryx, the Sudden Storm

Flash
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Besieged Viking Village

All creatures have "Boast — {1}: Put a +1/+1 counter on this creature." (Activate only if that creature attacked this turn and only once each turn.)
Whenever chaos ensues, put an indestructible counter on target creature you control that attacked this turn.

Antarctic Research Base

When you planeswalk to Antarctic Research Base and at the beginning of your upkeep, investigate.
Whenever chaos ensues, put X +1/+1 counters on target creature you control, where X is the number of artifacts you control. It becomes a Plant in addition to its other types.

The First Doctor

When The First Doctor enters the battlefield, search your library and/or graveyard for a card named TARDIS, reveal it, and put it into your hand. If you search your library this way, shuffle.
Whenever you cast a spell with cascade, put a +1/+1 counter on target artifact or creature.

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Grasp of Fate

When Grasp of Fate enters the battlefield, for each opponent, exile up to one target nonland permanent that player controls until Grasp of Fate leaves the battlefield. (Those permanents return under their owners' control.)

Strixhaven

Instant and sorcery spells players cast have demonstrate. (Whenever a player casts an instant or sorcery spell, they may copy it. If they do, they choose an opponent to also copy it. Players may choose new targets for their copies.)
Whenever chaos ensues, return up to one target instant or sorcery card from a graveyard to its owner's hand.

Plains

Ancestral Vision

Suspend 4—{U} (Rather than cast this card from your hand, pay {U} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Target player draws three cards.

Mountain

New Argive

Whenever a historic creature you control attacks, it gets +2/+2 until end of turn. (Artifacts, legendaries, and Sagas are historic.)
Whenever chaos ensues, reveal cards from the top of your library until you reveal a historic card. Put that card into your hand and the rest on the bottom of your library in a random order.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Amy's Home

When you planeswalk to Amy's Home and at the beginning of your upkeep, you may exile a nonland card from your hand with a number of time counters on it equal to its mana value. If it doesn't have suspend, it gains suspend.
Whenever chaos ensues, time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)

Bad Wolf Bay

At the beginning of combat on your turn, exile up to one target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.
When chaos ensues, cards can't enter the battlefield from exile this turn. Then planeswalk.

Leonin Abunas

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter the battlefield as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Fiery Islet

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice Fiery Islet: Draw a card.

Delayed Blast Fireball

Delayed Blast Fireball deals 2 damage to each opponent and each creature they control. If this spell was cast from exile, it deals 5 damage to each opponent and each creature they control instead.
Foretell {4}{R}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Spectrox Mines

When you planeswalk to Spectrox Mines and at the beginning of your upkeep, you lose 3 life and create a Treasure token.
Whenever chaos ensues, create a Food token and a 2/2 black Human Rogue creature token.

Throes of Chaos

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)