Flare of Duplication

You may sacrifice a nontoken red creature rather than pay this spell's mana cost.
Copy target instant or sorcery spell. You may choose new targets for the copy.

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Archmage Emeritus

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

Blue Sun's Twilight

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

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, Hope's Beacon deals X damage to each of up to two targets.

Dual Strike

When you next cast an instant or sorcery spell with mana value 4 or less this turn, copy that spell. You may choose new targets for the copy.
Foretell {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.)

Doublecast

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Arcane Bombardment

Whenever you cast your first instant or sorcery spell each turn, exile an instant or sorcery card at random from your graveyard. Then copy each card exiled with Arcane Bombardment. You may cast any number of the copies without paying their mana costs.

Elemental Eruption

Create a 4/4 red Dragon Elemental creature token with flying and prowess.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Echo Mage

Level up {1}{U} ({1}{U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-3
2/4
{U}{U}, {T}: Copy target instant or sorcery spell. You may choose new targets for the copy.
LEVEL 4+
2/5
{U}{U}, {T}: Copy target instant or sorcery spell twice. You may choose new targets for the copies.

Amphibian Downpour

Flash
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1.

Ral, Crackling Wit

Whenever you cast a noncreature spell, put a loyalty counter on Ral, Crackling Wit.
+1: Create a 1/1 blue and red Otter creature token with prowess.
−3: Draw three cards, then discard two cards.
−10: Draw three cards. You get an emblem with "Instant and sorcery spells you cast have storm." (Whenever you cast an instant or sorcery spell, copy it for each spell cast before it this turn.)

Double Vision

Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copy.

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Dual Casting

Enchant creature
Enchanted creature has "{R}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy."

Cut Your Losses

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.

Finale of Promise

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

Court of Vantress

When Court of Vantress enters, you become the monarch.
At the beginning of your upkeep, choose up to one other target enchantment or artifact. If you're the monarch, you may create a token that's a copy of it. If you're not the monarch, you may have Court of Vantress become a copy of it, except it has this ability.

Fiery Encore

Discard a card, then draw a card. When you discard a nonland card this way, Fiery Encore deals damage equal to that card's mana value to target creature or planeswalker.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Crackling Spellslinger

Flash
When Crackling Spellslinger enters, if you cast it, the next instant or sorcery spell you cast this turn has storm. (When you cast that spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Dualcaster Mage

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