Consider

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

Jeskai Elder

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever this creature deals combat damage to a player, you may draw a card. If you do, discard a card.

Sanguinary Mage

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

Murmuring Mystic

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

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Izzet Signet

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dwarven Forge-Chanter

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Spelleater Wolverine

This creature has double strike as long as there are three or more instant and/or sorcery cards in your graveyard.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Expedite

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

Serum Visions

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform this creature.

Delver of Secrets // Insectile Aberration

Festival Crasher

Whenever you cast an instant or sorcery spell, this creature gets +2/+0 until end of turn.

Prismari Campus

This land enters tapped.
{T}: Add {U} or {R}.
{4}, {T}: Scry 1.

Kiln Fiend

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

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Mountain

Negate

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.

Resculpt

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

Ornithopter of Paradise

Ponder

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

Burning Prophet

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

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Spellgorger Weird

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

Mistral Singer

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

Kessig Flamebreather

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Monastery Swiftspear

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

Deliberate

Snap

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

Maestros Theater

When this land enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Arcane Signet

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

Swiftwater Cliffs

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

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Island

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.)

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Counterspell

Into the Roil

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

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.

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Goblin Electromancer

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

Guttersnipe

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

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.)

Wee Dragonauts

Flying
Whenever you cast an instant or sorcery spell, this creature gets +2/+0 until end of turn.

Sky Theater Strix

Flying
Whenever you cast a noncreature spell, this creature gets +1/+0 until end of turn.

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.)

Goblin Wizardry

Create two 1/1 red Goblin Wizard creature tokens with prowess. (Whenever you cast a noncreature spell, they get +1/+1 until end of turn.)

Elusive Spellfist

Whenever you cast a noncreature spell, this creature gets +1/+0 until end of turn and can't be blocked this turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Command Tower

Highland Lake

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

Haunting Figment

Vigilance
This creature can't be blocked as long as you've cast an instant or sorcery spell this turn.

Frantic Search

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

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Battle Hymn

Bloodwater Entity

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

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.

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Nivix Cyclops

Defender
Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn and can attack this turn as though it didn't have defender.