Mystic Monastery

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

Brainsurge

Draw four cards, then put two cards from your hand on top of your library in any order.

Snap

Return target creature to its owner's hand. Untap up to two lands.

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.

Cursed Recording

Whenever you cast an instant or sorcery spell, put a time counter on Cursed Recording. Then if there are seven or more time counters on it, remove those counters and it deals 20 damage to you.
{T}: When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

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.

Time Beetle

Skulk (This creature can't be blocked by creatures with greater power.)
Parallel Universe — Whenever Time Beetle deals combat damage to a player, 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.)

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Arcane Signet

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

The Tenth Doctor

Allons-y! — Whenever you attack, exile cards from the top of your library until you exile a nonland card. Put three time counters on it. If it doesn't have suspend, it gains suspend.
Timey-Wimey — {7}: Time travel three times. Activate only as a sorcery. (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. Then do it two more times.)

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

As Foretold

At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on As Foretold.

Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.

Lightning Greaves

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

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.

Dinosaurs on a Spaceship

Vigilance, trample
Other Dinosaurs you control get +1/+1 and have vigilance and trample.
Suspend 4—{3}{R}{W}
Whenever a time counter is removed from Dinosaurs on a Spaceship while it's exiled, create a 2/2 red and white Dinosaur creature token with flying and haste.

The Eleventh Doctor

I. AM. TALKING! — Whenever The Eleventh Doctor deals combat damage to a player, you may exile a 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.
{2}: Target creature with power 3 or less can't be blocked this turn.

Rogue's Passage

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

Suspend

Exile target creature and put two time counters on it. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

One with the Multiverse

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.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Plains

Sonic Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Untap another target artifact.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{3}, {T}: Target creature can't be blocked this turn.

Sapphire Medallion

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

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.

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.

Crack in Time

Vanishing 3 (This enchantment enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Crack in Time enters and at the beginning of your first main phase, exile target creature an opponent controls until Crack in Time leaves the battlefield.

Thunderclap Drake

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}, Sacrifice Thunderclap Drake: When you next cast an instant or sorcery spell this turn, copy it for each time you've cast your commander from the command zone this game. You may choose new targets for the copies.

Mana Geyser

Add {R} for each tapped land your opponents control.

Exotic Orchard

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

Command Tower

Jhoira's Timebug

{T}: Choose target permanent you control or suspended card you own. If that permanent or card has a time counter on it, you may remove a time counter from it or put another time counter on it.

All of History, All at Once

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.)
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Jin-Gitaxias, Progress Tyrant

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

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.

Unwind

Counter target noncreature spell. Untap up to three lands.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Out of Time

When Out of Time enters, untap all creatures, then those creatures phase out until Out of Time leaves the battlefield. Put a time counter on Out of Time for each creature that phased out this way.
Vanishing (At the beginning of your upkeep, remove a time counter from this enchantment. When the last is removed, sacrifice it.)

Spelltwine

Exile target instant or sorcery card from your graveyard and target instant or sorcery card from an opponent's graveyard. Copy those cards. Cast the copies if able without paying their mana costs. Exile Spelltwine.

Aminatou's Augury

Exile the top eight cards of your library. You may put a land card from among them onto the battlefield. Until end of turn, for each nonland card type, you may cast a spell of that type from among the exiled cards without paying its mana cost.

Rivendell

Rivendell enters tapped unless you control a legendary creature.
{T}: Add {U}.
{1}{U}, {T}: Scry 2. Activate only if you control a legendary creature.

Rotating Fireplace

Rotating Fireplace enters tapped with a time counter on it.
{T}: Add an amount of {C} equal to the number of time counters on Rotating Fireplace.
{4}, {T}: Time travel. Activate only as a sorcery. (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.)

Rousing Refrain

Add {R} for each card in target opponent's hand. Until end of turn, you don't lose this mana as steps and phases end. Exile Rousing Refrain with three time counters on it.
Suspend 3—{1}{R} (Rather than cast this card from your hand, you may pay {1}{R} 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.)

The Wedding of River Song

Draw two cards, then you may exile a nonland card from your hand with a number of time counters on it equal to its mana value. Then target opponent does the same. Cards exiled this way that don't have suspend gain suspend.
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.)

Omniscience

You may cast spells from your hand without paying their mana costs.

Savor the Moment

Take an extra turn after this one. Skip the untap step of that turn.

Storm Herd

Create X 1/1 white Pegasus creature tokens with flying, where X is your life total.

Path of Ancestry

Path of Ancestry enters 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.)

Rose Tyler

Rose Tyler gets +1/+1 for each time counter on it.
Bad Wolf — Whenever Rose Tyler attacks, put a time counter on it for each suspended card you own and each other permanent you control with a time counter on it.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Fury Charm

Choose one —
• Destroy target artifact.
• Target creature gets +1/+1 and gains trample until end of turn.
• Remove two time counters from target permanent or suspended card.

Regenerations Restored

Vanishing 12 (This enchantment enters with twelve time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever one or more time counters are removed from Regenerations Restored, scry 1 and you gain 1 life. Then if Regenerations Restored has no time counters on it, exile it. When you do, take an extra turn after this one.

Four Knocks

Vanishing 4 (This enchantment enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
At the beginning of your first main phase, draw a card.

Sibylline Soothsayer

Temporal Foresight — When Sibylline Soothsayer enters, reveal cards from the top of your library until you reveal a nonland card with mana value 3 or greater. Exile that card with three time counters on it. If it doesn't have suspend, it gains suspend. Put the rest of the revealed cards on the bottom of your library in a random order.

Hit the Mother Lode

Discover 10. If the discovered card's mana value is less than 10, create a number of tapped Treasure tokens equal to the difference. (To discover 10, exile cards from the top of your library until you exile a nonland card with mana value 10 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

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.

Gandalf of the Secret Fire

Whenever you cast an instant or sorcery spell from your hand during an opponent's turn, exile that card with three time counters on it instead of putting it into your graveyard as it resolves. Then if the exiled card doesn't have suspend, it gains suspend. (At the beginning of your upkeep, remove a time counter. When the last is removed, you may play it without paying its mana cost.)

The Parting of the Ways

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile the top five cards of your library. For each nonland card exiled this way, put a number of time counters on that card equal to its mana value. If it doesn't have suspend, it gains suspend.
II — Time travel, then time travel.
III — For each opponent, destroy up to one target artifact that player controls.

Jhoira of the Ghitu

{2}, Exile a nonland card from your hand: Put four time counters on the exiled card. If it doesn't have suspend, it gains suspend. (At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. If it's a creature, it has haste.)

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.

Seething Song

Prairie Stream

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

Killer

Killer deals 3 damage to target creature and each other creature that shares a creature type with it.

Coward

Target creature can't block this turn and becomes a Coward in addition to its other types until end of turn.
Time travel.

Coward // Killer

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Hourglass of the Lost

{T}: Add {W}. Put a time counter on Hourglass of the Lost.
{T}, Remove X time counters from Hourglass of the Lost and exile it: Return each nonland permanent card with mana value X from your graveyard to the battlefield. Activate only as a sorcery.

Island

Amy Pond

Partner with Rory Williams (When this creature enters, target player may put Rory into their hand from their library, then shuffle.)
Whenever Amy Pond deals combat damage to a player, choose a suspended card you own and remove that many time counters from it.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Dance with Calamity

Shuffle your library. As many times as you choose, you may exile the top card of your library. If the total mana value of the cards exiled this way is 13 or less, you may cast any number of spells from among those cards without paying their mana costs.

Fellwar Stone

Glacial Fortress

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

Perilous Landscape

{T}: Add {C}.
{T}, Sacrifice Perilous Landscape: Search your library for a basic Island, Mountain, or Plains card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{R}{W} ({U}{R}{W}, Discard this card: Draw a card.)

Wibbly-wobbly, Timey-wimey

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.)
Draw a card.

Time Stretch

Target player takes two extra turns after this one.

Mountain

Ecstatic Beauty

Exile the top three cards of your library. You may play those cards until end of turn. Put four time counters on each of those cards that has suspend.
Suspend 4—{R}

Reverse the Sands

Redistribute any number of players' life totals. (Each of those players gets one life total back.)