Guttersnipe

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

Fell Beast's Shriek

Each opponent chooses a creature they control. Tap and goad the chosen creatures. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)
Splice onto instant or sorcery {2}{U}{R} (As you cast an instant or sorcery 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.)

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Crash Through

Creatures you control gain trample until end of turn. (Each of those creature can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Pongify

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

Case of the Ransacked Lab

Instant and sorcery spells you cast cost {1} less to cast.
To solve — You've cast four or more instant and sorcery spells this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast an instant or sorcery spell, draw a card.

Thought Vessel

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

Brainstorm

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

Pearl of Wisdom

This spell costs {1} less to cast if you control an Otter.
Draw two cards.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Goblin Electromancer

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

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

Consider

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

Island

Izzet Signet

Sol Ring

Mountain

Blasphemous Act

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

Propaganda

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

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

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.

Frantic Search

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

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Snap

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

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Rapid Augmenter

Haste
Whenever another creature you control with base power 1 enters, it gains haste until end of turn.
Whenever another creature you control enters, if it wasn't cast, put a +1/+1 counter on this creature and this creature can't be blocked this turn.

Curse of the Swine

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

Resculpt

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

Kiln Fiend

Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Young Pyromancer

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

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Cast into the Fire

Choose one —
• Cast into the Fire deals 1 damage to each of up to two target creatures.
• Exile target artifact.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Quicken

The next sorcery spell you cast this turn can be cast as though it had flash. (It can be cast any time you could cast an instant.)
Draw a card.

Counterspell

Negate

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.

Stormchaser Mage

Flying, haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Leap

Target creature gains flying until end of turn.
Draw a card.

Ice Out

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
This spell costs {1} less to cast if it's bargained.
Counter target spell.

Flare of Denial

You may sacrifice a nontoken blue creature rather than pay this spell's mana cost.
Counter target spell.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Alania, Divergent Storm

Whenever you cast a spell, if it's the first instant spell, the first sorcery spell, or the first Otter spell other than Alania you've cast this turn, you may have target opponent draw a card. If you do, copy that spell. You may choose new targets for the copy.

Bilbo, Retired Burglar

When Bilbo enters or leaves the battlefield, the Ring tempts you.
Whenever Bilbo deals combat damage to a player, create a Treasure token.

Bria, Riptide Rogue

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Other creatures you control have prowess. (If a creature has multiple instances of prowess, each triggers separately.)
Whenever you cast a noncreature spell, target creature you control can't be blocked this turn.

Copy Enchantment

You may have this enchantment enter as a copy of any enchantment on the battlefield.

Don't Make a Sound

Counter target spell unless its controller pays {2}. If they do, 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.)

Dreadhorde Arcanist

Trample
Whenever this creature attacks, you may cast target instant or sorcery card with mana value less than or equal to this creature's power from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.

Sprite Dragon

Flying, haste
Whenever you cast a noncreature spell, put a +1/+1 counter on this creature.

Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Galvanic Iteration

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
Flashback {1}{U}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Empty the Warrens

Create two 1/1 red Goblin creature tokens.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

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.

Third Path Iconoclast

Whenever you cast a noncreature spell, create a 1/1 colorless Soldier artifact creature token.

Archmage Emeritus

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

Warlord's Fury

Creatures you control gain first strike until end of turn.
Draw a card.

Jace's Sanctum

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

Gitaxian Spellstalker

Trample, ward {2}, prowess, prowess (Each instance of prowess triggers separately.)

Khenra Spellspear

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{3}{U/P}: Transform this creature. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)