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.)

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Volcanic Vision

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's mana value to each creature your opponents control. Exile Volcanic Vision.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Future Sight

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

Quantum Misalignment

Create a token that's a copy of target creature you control, except it isn't legendary.
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.)

The Thirteenth Doctor

Paradox — Whenever you cast a spell from anywhere other than your hand, put a +1/+1 counter on target creature.
Team TARDIS — At the beginning of your end step, untap each creature you control with a counter on it.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Yasmin Khan

{T}: Exile the top card of your library. Until your next end step, you may play it.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Game Trail

As Game Trail enters, you may reveal a Mountain or Forest card from your hand. If you don't, Game Trail enters tapped.
{T}: Add {R} or {G}.

Sheltered Thicket

({T}: Add {R} or {G}.)
Sheltered Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Lunar Hatchling

Flying, trample
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)
Escape—{4}{G}{U}, Exile a land you control, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Arcane Signet

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

River Song

Meet in Reverse — You draw cards from the bottom of your library rather than the top.
Spoilers — Whenever an opponent scries, surveils, or searches their library, put a +1/+1 counter on River Song. Then River Song deals damage to that player equal to its power.

Izzet Signet

Unlikely Meeting

Search your library for a Doctor card, reveal it, put it into your hand, then shuffle.

Twice Upon a Time

Cast this spell only if you control two or more Doctors.
Take an extra turn after this one. Exile Twice Upon a Time.

Twice Upon a Time // Unlikely Meeting

Clara Oswald

Impossible Girl — If Clara Oswald is your commander, choose a color before the game begins. Clara Oswald is the chosen color.
If a triggered ability of a Doctor you control triggers, that ability triggers an additional time.
Doctor's companion (You can have two commanders if the other is the Doctor.)

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.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Wand of Wonder

{4}, {T}: Roll a d20. Each opponent exiles cards from the top of their library until they exile an instant or sorcery card, then shuffles the rest into their library. You may cast up to X instant and/or sorcery spells from among cards exiled this way without paying their mana costs.
1—9 | X is one.
10—19 | X is two.
20 | X is three.

Heaven Sent

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Investigate.
III — Heaven Sent deals 1 damage to each opponent. Then if an opponent has 0 or less life, draw seven cards. Otherwise, exile Heaven Sent and you may cast it this turn.

Mountain

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two 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.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Melek, Izzet Paragon

Play with the top card of your library revealed.
You may cast instant and sorcery spells from the top of your library.
Whenever you cast an instant or sorcery spell from your library, copy it. You may choose new targets for the copy.

Counterspell

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.

Sol Ring

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Temple of Abandon

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {G}.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Etali, Primal Storm

Whenever Etali 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.

Wreck and Rebuild

Choose one —
• Destroy target artifact or enchantment.
• Mill five cards, then you may put a land card from your graveyard onto the battlefield tapped.
Flashback {3}{R}{G}

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.

Gallifrey Council Chamber

When Gallifrey Council Chamber enters, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Time Lord or Alien spell or activate an ability of a Time Lord or Alien.

Twinning Staff

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

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.)

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Apex of Power

Exile the top seven cards of your library. Until end of turn, you may cast spells from among them.
If this spell was cast from your hand, add ten mana of any one color.

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Start the TARDIS

Surveil 2, then draw a card. You may planeswalk. (To 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.)
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

The Fugitive Doctor

When The Fugitive Doctor enters, investigate.
Whenever The Fugitive Doctor attacks, you may sacrifice a Clue. When you do, target instant or sorcery card in your graveyard gains flashback {2}{R}{G} until end of turn. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Ryan Sinclair

Whenever Ryan attacks, exile cards from the top of your library until you exile a nonland card. You may cast the exiled card without paying its mana cost if it's a spell with mana value less than or equal to Ryan's power. Put the exiled cards not cast this way on the bottom of your library in a random order.
Doctor's companion (You can have two commanders if the other is the Doctor.)

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.

Confession Dial

When Confession Dial enters, surveil 3.
{T}: Target legendary creature card in your graveyard gains escape until end of turn. The escape cost is equal to its mana cost plus exile three other cards from your graveyard. (You may cast it from your graveyard for its escape cost this turn.)

Forest

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.

Bigger on the Inside

Enchant artifact or land
Enchanted permanent has "{T}: Target player adds two mana of any one color. The next spell they cast this turn has cascade." (When they cast their next spell, they exile cards from the top of their library until they exile a nonland card that costs less. They may cast it without paying its mana cost. They put the exiled cards on the bottom in a random order.)

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Stormcarved Coast

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

Kodama's Reach

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Mana Leak

Counter target spell unless its controller pays {3}.

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

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.)

Flatline

Creatures your opponents control have base power and toughness 0/1 until end of turn.

Jaya Ballard

+1: Add {R}{R}{R}. Spend this mana only to cast instant or sorcery spells.
+1: Discard up to three cards, then draw that many cards.
−8: You get an emblem with "You may cast instant and sorcery spells from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead."

Return the Past

During your turn, each instant and sorcery card in your graveyard has flashback. Its flashback cost is equal to its mana cost.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Johann, Apprentice Sorcerer

You may look at the top card of your library any time.
Once each turn, you may cast an instant or sorcery spell from the top of your library. (You still pay its costs. Timing rules still apply.)

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

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.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

TARDIS

Flying
Whenever TARDIS attacks, if you control a Time Lord, the next spell you cast this turn has cascade and you may planeswalk.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Exotic Orchard

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

Island

Crashing Footfalls

Suspend 4—{G} (Rather than cast this card from your hand, pay {G} 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.)
Create two 4/4 green Rhino creature tokens with trample.

Frostboil Snarl

As Frostboil Snarl enters, you may reveal an Island or Mountain card from your hand. If you don't, Frostboil Snarl enters tapped.
{T}: Add {U} or {R}.

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Rhystic Study

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

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Vineglimmer Snarl

As Vineglimmer Snarl enters, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters tapped.
{T}: Add {G} or {U}.

Edgin, Larcenous Lutenist

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 you cast your second spell each turn, goad target creature an opponent controls.

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Impending Flux

Paradox — Impending Flux deals X damage to each opponent and each creature they control, where X is 1 plus the number of spells you've cast from anywhere other than your hand this turn.
Foretell {1}{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.)

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Truth or Consequences

Secret council — Each player secretly votes for truth or consequences, then those votes are revealed. You draw cards equal to the number of truth votes. Then choose an opponent at random. Truth or Consequences deals 3 damage to that player for each consequences vote.