Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Arcane Signet

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

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

Geralf, the Fleshwright

Whenever you cast a spell during your turn other than your first spell that turn, create a 2/2 blue and black Zombie Rogue creature token.
Whenever a Zombie you control enters, put a +1/+1 counter on it for each other Zombie that entered the battlefield under your control this turn.

Serum Visions

Temple of Cyclical Time

(Transforms from Ojer Pakpatiq, Deepest Epoch.)
{T}: Add {U}. Remove a time counter from Temple of Cyclical Time.
{2}{U}, {T}: Transform Temple of Cyclical Time. Activate only if it has no time counters on it and only as a sorcery.

Ojer Pakpatiq, Deepest Epoch

Flying
Whenever you cast an instant spell from your hand, it gains rebound. (Exile it as it resolves. At the beginning of your next upkeep, you may cast it from exile without paying its mana cost.)
When Ojer Pakpatiq dies, return it to the battlefield tapped and transformed under its owner's control with three time counters on it.

Ojer Pakpatiq, Deepest Epoch // Temple of Cyclical Time

Fountainport Bell

When Fountainport Bell enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.
{1}, Sacrifice Fountainport Bell: Draw a card.

Behold the Multiverse

Scry 2, then draw two cards.
Foretell {1}{U} (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.)

Command Tower

Island

Frantic Search

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

Sapphire Medallion

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

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

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.")

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Sage of the Beyond

Flying
Spells you cast from anywhere other than your hand cost {2} less to cast.
Foretell {4}{U} (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.)

Into the Flood Maw

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Return target creature an opponent controls to its owner's hand. If the gift was promised, instead return target nonland permanent an opponent controls to its owner's hand.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (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.)

Reliquary Tower

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

Spellbook

Counterspell

Cephalid Coliseum

{T}: Add {U}. Cephalid Coliseum deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Slickshot Lockpicker

When Slickshot Lockpicker enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
Plot {2}{U} (You may pay {2}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Smirking Spelljacker

Flash
Flying
When Smirking Spelljacker enters, exile target spell an opponent controls.
Whenever Smirking Spelljacker attacks, if a card is exiled with it, you may cast the exiled card without paying its mana cost.

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Mind Stone

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

Thought Vessel

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.

Brainstorm

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

Jace Reawakened

You can't cast Jace Reawakened during your first, second, or third turns of the game.
+1: Draw a card, then discard a card.
+1: You may exile a nonland card with mana value 3 or less from your hand. If you do, it becomes plotted.
−6: Until end of turn, whenever you cast a spell, copy it. You may choose new targets for the copy.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

The Key to the Vault

Whenever equipped creature deals combat damage to a player, look at that many cards from the top of your library. You may exile a nonland card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.
Equip {2}{U}

Lock and Load

Draw a card, then draw a card for each other instant and sorcery spell you've cast this turn.
Plot {3}{U} (You may pay {3}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Zuran Orb

Ponder

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

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Fblthp, Lost on the Range

Ward {2}
You may look at the top card of your library any time.
The top card of your library has plot. The plot cost is equal to its mana cost.
You may plot nonland cards from the top of your library.

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.

Spidersilk Net

Equipped creature gets +0/+2 and has reach. (It can block creatures with flying.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Season of Weaving

Choose up to five {P} worth of modes. You may choose the same mode more than once.
{P} — Draw a card.
{P}{P} — Choose an artifact or creature you control. Create a token that's a copy of it.
{P}{P}{P} — Return each nonland, nontoken permanent to its owner's hand.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

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.)

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Aetherize

Return all attacking creatures to their owner's hand.

High Tide

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

Surge of Brilliance

Paradox — Draw a card for each spell you've cast this turn from anywhere other than your hand.
Foretell {1}{U} (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.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Saw It Coming

Counter target spell.
Foretell {1}{U} (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.)

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.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Snap

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

Hydroelectric Laboratory

As Hydroelectric Laboratory enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When Hydroelectric Specimen enters, you may change the target of target instant or sorcery spell with a single target to Hydroelectric Specimen.

Hydroelectric Specimen // Hydroelectric Laboratory

Otterball Antics

Create a 1/1 blue and red Otter creature token with prowess. If this spell was cast from anywhere other than your hand, put a +1/+1 counter on that creature. (Whenever you cast a noncreature spell, a creature with prowess gets +1/+1 until end of turn.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Negate

Portent of Calamity

Reveal the top X cards of your library. For each card type, you may exile a card of that type from among them. Put the rest into your graveyard. You may cast a spell from among the exiled cards without paying its mana cost if you exiled four or more cards this way. Then put the rest of the exiled cards into your hand.

Fortune Teller's Talent

(Gain the next level as a sorcery to add its ability.)
You may look at the top card of your library any time.
{3}{U}: Level 2
As long as you've cast a spell this turn, you may play cards from the top of your library.
{2}{U}: Level 3
Spells you cast from anywhere other than your hand cost {2} less to cast.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

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.

Archway of Innovation

Archway of Innovation enters tapped unless you control an Island.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Coral Atoll

Coral Atoll enters tapped.
When Coral Atoll enters, sacrifice it unless you return an untapped Island you control to its owner's hand.
{T}: Add {C}{U}.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Gandalf, Friend of the Shire

Flash
You may cast sorcery spells as though they had flash.
Whenever the Ring tempts you, if you chose a creature other than Gandalf, Friend of the Shire as your Ring-bearer, draw a card.

Soporific Springs

As Soporific Springs enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Lightning Greaves

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

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.

Plan the Heist

Surveil 3 if you have no cards in hand. Then draw three cards. (To surveil 3, look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Plot {3}{U} (You may pay {3}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Desynchronization

Return each nonland permanent that's not historic to its owner's hand. (Artifacts, legendaries, and Sagas are historic.)

Throne of Eldraine

As Throne of Eldraine enters, choose a color.
{T}: Add four mana of the chosen color. Spend this mana only to cast monocolored spells of that color.
{3}, {T}: Draw two cards. Spend only mana of the chosen color to activate this ability.

Step Between Worlds

Each player may shuffle their hand and graveyard into their library. Each player who does draws seven cards. Exile Step Between Worlds.
Plot {4}{U}{U} (You may pay {4}{U}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Osgood, Operation Double

When you cast this spell, create a token that's a copy of it, except it isn't legendary.
{T}: Add {C}. Spend this mana only to cast an artifact spell or activate an ability of an artifact.
Paradox — Whenever you cast a spell from anywhere other than your hand, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")