Ideas Unbound

Draw three cards. Discard three cards at the beginning of the next end step.

Jace's Sanctum

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1.

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{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.)

Adaptive Training Post

Whenever you cast an instant or sorcery spell, if this artifact has fewer than three charge counters on it, put a charge counter on it.
Remove three charge counters from this artifact: When you next cast an instant or sorcery spell this turn, copy it and you may choose new targets for the copy.

Inner Calm, Outer Strength

Target creature gets +X/+X until end of turn, where X is the number of cards in your hand.

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}.

Murmurs from Beyond

Reveal the top three cards of your library. An opponent chooses one of them. Put that card into your graveyard and the rest into your hand.

Peer Through Depths

Look at the top five cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Sift Through Sands

Draw two cards, then discard a card.
If you've cast a spell named Peer Through Depths and a spell named Reach Through Mists this turn, you may search your library for a card named The Unspeakable, put it onto the battlefield, then shuffle.

Thornwood Falls

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {U}.

Fiery Inscription

When this enchantment enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, this enchantment deals 2 damage to each opponent.

Tangled Islet

({T}: Add {G} or {U}.)
This land enters tapped.

Riku of Two Reflections

Whenever you cast an instant or sorcery spell, you may pay {U}{R}. If you do, copy that spell. You may choose new targets for the copy.
Whenever another nontoken creature you control enters, you may pay {G}{U}. If you do, create a token that's a copy of that creature.

Storm-Kiln Artist

This creature gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Gaze of Adamaro

Gaze of Adamaro deals damage to target player equal to the number of cards in that player's hand.

Loam Dweller

Whenever you cast a Spirit or Arcane spell, you may put a land card from your hand onto the battlefield tapped.

Joyous Respite

You gain 1 life for each land you control.

Archmage Emeritus

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

Nourishing Shoal

You may exile a green card with mana value X from your hand rather than pay this spell's mana cost.
You gain X life.

Temple of Mystery

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 {G} or {U}.

Stream of Consciousness

Target player shuffles up to four target cards from their graveyard into their library.

Krark, the Thumbless

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Eerie Procession

Search your library for an Arcane card, reveal that card, put it into your hand, then shuffle.

Temple of Cyclical Time

(Transforms from Ojer Pakpatiq, Deepest Epoch.)
{T}: Add {U}. Remove a time counter from this land.
{2}{U}, {T}: Transform this land. 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

Vital Surge

You gain 3 life.
Splice onto Arcane {1}{G} (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.)

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

The Unspeakable

Flying, trample
Whenever The Unspeakable deals combat damage to a player, you may return target Arcane card from your graveyard to your hand.

Mountain

Forest

Niblis of Frost

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Command Tower

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

Toils of Night and Day

You may tap or untap target permanent, then you may tap or untap another target permanent.

Through the Breach

You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice that creature at the beginning of the next end step.
Splice onto Arcane {2}{R}{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.)

Electro, Assaulting Battery

Flying
You don't lose unspent red mana as steps and phases end.
Whenever you cast an instant or sorcery spell, add {R}.
When Electro leaves the battlefield, you may pay {X}. When you do, he deals X damage to target player.

Evermind

(Nonexistent mana costs can't be paid.)
Draw a card.
Splice onto Arcane {1}{U} (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.)

Thriving Grove

This land enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Thousand-Year Storm

Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.

Blind with Anger

Untap target nonlegendary creature and gain control of it until end of turn. That creature gains haste until end of turn.

Crushing Pain

Crushing Pain deals 6 damage to target creature that was dealt damage this turn.

Strength of Cedars

Target creature gets +X/+X until end of turn, where X is the number of lands you control.

Psychic Puppetry

You may tap or untap target permanent.
Splice onto Arcane {U} (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.)

Reweave

Target permanent's controller sacrifices it. If the player does, they reveal cards from the top of their library until they reveal a permanent card that shares a card type with the sacrificed permanent, put that card onto the battlefield, then shuffle.
Splice onto Arcane {2}{U}{U} (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.)

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Crack the Earth

Each player sacrifices a permanent of their choice.

Cursed Recording

Whenever you cast an instant or sorcery spell, put a time counter on this artifact. 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.

Final Iteration

Flying
Wizards you control get +2/+1 and have flying.
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token.

Docent of Perfection

Flying
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token. Then if you control three or more Wizards, transform this creature.

Docent of Perfection // Final Iteration

Caldera Pyremaw

Flying
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature. Then this creature deals damage equal to its power to target opponent.

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Strange Inversion

Switch target creature's power and toughness until end of turn.
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.)

Invocation of the Founders

Whenever you cast an instant or sorcery spell from your hand, you may copy that spell. You may choose new targets for the copy.

Invasion of Arcavios

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, search your library, graveyard, and/or outside the game for an instant or sorcery card you own, reveal it, and put it into your hand. If you search your library this way, shuffle.

Invasion of Arcavios // Invocation of the Founders

Feed the Clan

You gain 5 life.
Ferocious — You gain 10 life instead if you control a creature with power 4 or greater.

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

Temple of Epiphany

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 {U} or {R}.

Skyfire Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may gain control of target creature with that spell's mana value until end of turn.

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.)

Roar of Jukai

If you control a Forest, each blocked creature gets +2/+2 until end of turn.
Splice onto Arcane—An opponent gains 5 life. (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.)

Reach Through Mists

Chandra, Hope's Beacon

Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy. This ability triggers only once each turn.
+2: Add two mana in any combination of colors.
+1: Exile the top five cards of your library. Until the end of your next turn, you may cast an instant or sorcery spell from among those exiled cards.
−X: Chandra deals X damage to each of up to two targets.

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.

Wear Away

Destroy target artifact or enchantment.
Splice onto Arcane {3}{G} (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.)

Savage Mansion

This land enters tapped.
{T}: Add {R} or {G}.
{4}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Exalted Flamer of Tzeentch

Sorcerous Inspiration — At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Fire of Tzeentch — Whenever you cast an instant or sorcery spell, this creature deals 1 damage to each opponent.

Deekah, Fractal Theorist

Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is that spell's mana value.
{3}{U}: Target creature token can't be blocked this turn.

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Cut the Earthly Bond

Return target enchanted permanent to its owner's hand.

Sol Ring

Gandalf the Grey

Whenever you cast an instant or sorcery spell, choose one that hasn't been chosen —
• You may tap or untap target permanent.
• Gandalf deals 3 damage to each opponent.
• Copy target instant or sorcery spell you control. You may choose new targets for the copy.
• Put Gandalf on top of its owner's library.

Molten Tributary

({T}: Add {U} or {R}.)
This land enters tapped.

Island

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, this creature gets +4/+0 until end of turn.

Vivi Ornitier

{0}: Add X mana in any combination of {U} and/or {R}, where X is Vivi Ornitier's power. Activate only during your turn and only once each turn.
Whenever you cast a noncreature spell, put a +1/+1 counter on Vivi Ornitier and it deals 1 damage to each opponent.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Riddlesmith

Whenever you cast an artifact spell, you may draw a card. If you do, discard a card.

Glacial Ray

Glacial Ray deals 2 damage to any target.
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.)

Consuming Vortex

Return target creature to its owner's hand.
Splice onto Arcane {3}{U} (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.)

Rugged Highlands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {G}.