Brainstorm

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

Run Away Together

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

Murmuring Mystic

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

Spellgorger Weird

Whenever you cast a noncreature spell, put a +1/+1 counter on Spellgorger Weird.

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.)

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

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.)

Seething Song

Bloodwater Entity

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Bloodwater Entity enters the battlefield, you may put target instant or sorcery card from your graveyard on top of your library.

Deliberate

Star Compass

Star Compass enters the battlefield tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Forktail Sweep

Forktail Sweep deals 1 damage to each creature you don't control. (Then exile this card. You may cast the creature later from exile.)

Fang Dragon

Fang Dragon // Forktail Sweep

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Moonsnare Prototype

{T}, Tap an untapped artifact or creature you control: Add {C}.
Channel — {4}{U}, Discard Moonsnare Prototype: The owner of target nonland permanent puts it on the top or bottom of their library.

Firebrand Archer

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Tamiyo's Epiphany

Goblin Electromancer

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

Snap

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

Izzet Signet

Mana Geyser

Add {R} for each tapped land your opponents control.

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.)

Ponder

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

Guttersnipe

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

Thought Vessel

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

High Tide

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

Sky Diamond

Sky Diamond enters the battlefield tapped.
{T}: Add {U}.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Serum Visions

Consider

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

Frantic Search

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

Temporal Fissure

Return target permanent to its owner's hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

Sword Coast Serpent can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Burning Prophet

Whenever you cast a noncreature spell, Burning Prophet gets +1/+0 until end of turn, then scry 1.

Everflowing Chalice

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