Negate

Heartfire Immolator

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{R}, Sacrifice this creature: It deals damage equal to its power to target creature or planeswalker.

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.

Johann, Apprentice Sorcerer

You may look at the top card of your library any time.
Once each turn, you may cast an instant or sorcery spell from the top of your library. (You still pay its costs. Timing rules still apply.)

Warlord's Fury

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

Bloodwater Entity

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

Frantic Search

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

High Tide

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

Dazzling Denial

Counter target spell unless its controller pays {2}. If you control a Bird, counter that spell unless its controller pays {4} instead.

Counterspell

Kraum, Violent Cacophony

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Kraum, Violent Cacophony and draw a card.

Strike It Rich

Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

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.

Highland Lake

Highland Lake enters tapped.
{T}: Add {U} or {R}.

Winged Words

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

Nivix Cyclops

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

Expedite

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

Frostboil Snarl

As Frostboil Snarl enters, you may reveal an Island or Mountain card from your hand. If you don't, Frostboil Snarl enters tapped.
{T}: Add {U} or {R}.

Thriving Bluff

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

Swiftwater Cliffs

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

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Mountain

Enter the Enigma

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

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Twinferno

Choose one —
• When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Goblin Electromancer

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

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Cyclops Superconductor

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Cyclops Superconductor enters, you get {E}{E}{E} (three energy counters).
When Cyclops Superconductor dies, you may pay {E}{E}{E}. When you do, Cyclops Superconductor deals damage equal to its power to any target.

Ghitu Amplifier

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
When Ghitu Amplifier enters, if it was kicked, return target creature an opponent controls to its owner's hand.
Whenever you cast an instant or sorcery spell, Ghitu Amplifier gets +2/+0 until end of turn.

Spellgorger Weird

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

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.

Treasure Cruise

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

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.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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.)

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.

Maestros Theater

When Maestros Theater 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.

Burning Prophet

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

Haze of Rage

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Creatures you control get +1/+0 until end of turn.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Adeliz, the Cinder Wind

Flying, haste
Whenever you cast an instant or sorcery spell, Wizards you control get +1/+1 until end of turn.

Island

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.

Crackling Cyclops

Whenever you cast a noncreature spell, this creature gets +3/+0 until end of turn.

Sky Diamond

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Arcane Signet

Consider

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

Abrade

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

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 Khenra Spellspear. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Khenra Spellspear // Gitaxian Spellstalker

Crackling Drake

Flying
Crackling Drake's power is equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
When Crackling Drake enters, draw a card.

Otterball Antics

Create a 1/1 blue and red Otter creature token with prowess. If this spell was cast from anywhere other than your hand, put a +1/+1 counter on that creature. (Whenever you cast a noncreature spell, a creature with prowess gets +1/+1 until end of turn.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Stormchaser Mage

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

Exotic Orchard

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

Jhessian Thief

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

Quick Study

Escape Tunnel

{T}, Sacrifice Escape Tunnel: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice Escape Tunnel: Target creature with power 2 or less can't be blocked this turn.

Triton Wavebreaker

Bestow {1}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
As long as Triton Wavebreaker is a creature, it has prowess. (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Enchanted creature gets +1/+1 and has prowess.

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.)

Spellheart Chimera

Flying, trample
Spellheart Chimera's power is equal to the number of instant and sorcery cards in your graveyard.

Wee Dragonauts

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

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Kiln Fiend

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

Thriving Isle

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

Fellwar Stone

Talrand, Sky Summoner

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

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

Sol Ring

Evolving Wilds

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

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Slip Through Space

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

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.

Mocking Sprite

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

Storm Skreelix

Flying
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, Storm Skreelix gets +2/+0 until end of turn.

Umara Mystic

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

Dynacharge

Target creature you control gets +2/+0 until end of turn.
Overload {2}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Blow Off Steam

Blow Off Steam deals 1 damage to any target. (Then exile this card. You may cast the creature later from exile.)

Frolicking Familiar

Flying
Whenever you cast an instant or sorcery spell, Frolicking Familiar gets +1/+1 until end of turn.

Frolicking Familiar // Blow Off Steam

Thrill of Possibility

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

Sprite Dragon

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

Mystic Peak

As Mystic Peak enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}.

Pinnacle Monk

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Pinnacle Monk enters, return target instant or sorcery card from your graveyard to your hand.

Pinnacle Monk // Mystic Peak

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Festival Crasher

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

Electrostatic Infantry

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Electrostatic Infantry.