Mercurial Spelldancer

Mercurial Spelldancer can't be blocked.
Whenever you cast a noncreature spell, put an oil counter on Mercurial Spelldancer.
Whenever Mercurial Spelldancer deals combat damage to a player, you may remove two oil counters from it. If you do, when you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on Mindsplice Apparatus.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on Mindsplice Apparatus.

Naru Meha, Master Wizard

Flash
When Naru Meha, Master Wizard enters, copy target instant or sorcery spell you control. You may choose new targets for the copy.
Other Wizards you control get +1/+1.

Mind Stone

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

Pull from Tomorrow

Snap

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

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Sapphire Medallion

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

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

Trawler Drake

Flying
Trawler Drake enters with an oil counter on it.
Trawler Drake gets +1/+1 for each oil counter on it.
Whenever you cast a noncreature spell, put an oil counter on Trawler Drake.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Lightning Greaves

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

Pollywog Prodigy

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever an opponent casts a noncreature spell with mana value less than Pollywog Prodigy's power, draw a card.

Hurkyl, Master Wizard

At the beginning of your end step, if you've cast a noncreature spell this turn, reveal the top five cards of your library. For each card type among noncreature spells you've cast this turn, you may put a card of that type from among the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Gale's Redirection

Exile target spell, then roll a d20 and add that spell's mana value.
1—14 | You may cast the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
15+ | You may cast the exiled card without paying its mana cost for as long as it remains exiled.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Reliquary Tower

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

Consider

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

Domineering Will

Target player gains control of up to three target nonattacking creatures until end of turn. Untap those creatures. They block this turn if able.

Campfire

{1}, {T}: You gain 2 life.
{2}, {T}, Exile Campfire: Put all commanders you own from the command zone and from your graveyard into your hand. Then shuffle your graveyard into your library.

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Counterspell

Sky Diamond

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Iymrith, Desert Doom

Flying
Iymrith, Desert Doom has ward {4} as long as it's untapped.
Whenever Iymrith deals combat damage to a player, draw a card. Then if you have fewer than three cards in hand, draw cards equal to the difference.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Cone of Cold

Roll a d20.
1—9 | Tap all creatures your opponents control.
10—19 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps.
20 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps. Until your next turn, creatures your opponents control enter tapped.

Contact Other Plane

Roll a d20.
1—9 | Draw two cards.
10—19 | Scry 2, then draw two cards.
20 | Scry 3, then draw three cards.

Brainsurge

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

An Offer You Can't Refuse

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

Rapid Hybridization

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

Arcane Signet

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

Negate

Spectral Deluge

Return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.
Foretell {1}{U}{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.)

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Ponder

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

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.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

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.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Frantic Search

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

Aether Gale

Return six target nonland permanents to their owners' hands.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Rogue's Passage

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

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis the Omnipotent to its owner's hand.

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Thought Vessel

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

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.

Quick Study

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Zenith Chronicler

Whenever a player casts their first multicolored spell each turn, each other player draws a card.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Island

Arcane Proxy

Prototype {1}{U}{U} — 2/1 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
When Arcane Proxy enters, if you cast it, exile target instant or sorcery card with mana value less than or equal to Arcane Proxy's power from your graveyard. Copy that card. You may cast the copy without paying its mana cost.

Minor Misstep

Counter target spell with mana value 1 or less.

Sol Ring

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.