Don't Have

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Have

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Island

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Windfall

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

Unruly Catapult

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

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Temple of Epiphany

Temple of Epiphany enters tapped.
When Temple of Epiphany enters, scry 1.
{T}: Add {U} or {R}.

Young Pyromancer

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

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Niv-Mizzet, Visionary

Flying
You have no maximum hand size.
Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

Arcane Signet

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

Sigil of Sleep

Enchant creature
Whenever enchanted creature deals damage to a player, return target creature that player controls to its owner's hand.

Counterspell

Izzet Signet

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Coruscation Mage

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Exalted Flamer of Tzeentch

Sorcerous Inspiration — At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Fire of Tzeentch — Whenever you cast an instant or sorcery spell, Exalted Flamer of Tzeentch deals 1 damage to each opponent.

Jwari Ruins

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Negate

Lobber Crew

Defender
{T}: Lobber Crew deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap Lobber Crew.

Shivan Gorge

{T}: Add {C}.
{2}{R}, {T}: Shivan Gorge deals 1 damage to each opponent.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Smash to Dust

Choose one —
• Destroy target artifact.
• Destroy target creature with defender.
• Smash to Dust deals 1 damage to each creature your opponents control.

Stella Lee, Wild Card

Whenever you cast your second spell each turn, exile the top card of your library. Until the end of your next turn, you may play that card.
{T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. Activate only if you've cast three or more spells this turn.

Neurok Stealthsuit

Equipped creature has shroud. (It can't be the target of spells or abilities.)
{U}{U}: Attach Neurok Stealthsuit to target creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Archmage Emeritus

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

Kessig Flamebreather

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

Fellwar Stone

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

Saw It Coming

Counter target spell.
Foretell {1}{U} (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.)

Giggling Skitterspike

Indestructible
Whenever Giggling Skitterspike attacks, blocks, or becomes the target of a spell, it deals damage equal to its power to each opponent.
{5}: Monstrosity 5. (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)

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

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Invert Polarity

Choose target spell, then flip a coin. If you win the flip, gain control of that spell and you may choose new targets for it. If you lose the flip, counter that spell.

Sky Diamond

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}.

Ophidian Eye

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Fire Diamond

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

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Consider

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

Peek

Look at target player's hand.
Draw a card.

Gleeful Arsonist

Whenever an opponent casts a noncreature spell, Gleeful Arsonist deals damage equal to its power to that player.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Tunneling Geopede

Landfall — Whenever a land you control enters, Tunneling Geopede deals 1 damage to each opponent.

Command Tower

Treasure Cruise

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

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.

Ferrous Lake

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, Erebor Flamesmith deals 1 damage to each opponent.

Sawblade Scamp

Haste
Whenever you cast a noncreature spell, put an oil counter on Sawblade Scamp.
{T}, Remove an oil counter from Sawblade Scamp: It deals 1 damage to each opponent.

Mountain

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, 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.

Firespitter Whelp

Flying
Whenever you cast a noncreature or Dragon spell, Firespitter Whelp deals 1 damage to each opponent.

Hydroelectric Laboratory

As Hydroelectric Laboratory enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When Hydroelectric Specimen enters, you may change the target of target instant or sorcery spell with a single target to Hydroelectric Specimen.

Hydroelectric Specimen // Hydroelectric Laboratory

Wash Away

Cleave {1}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Counter target spell [that wasn't cast from its owner's hand].

Izzet Boilerworks

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

Third Path Iconoclast

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

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Sol Ring

Razorkin Needlehead

Razorkin Needlehead has first strike during your turn.
Whenever an opponent draws a card, Razorkin Needlehead deals 1 damage to them.

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.

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.)

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.

Steam Clean

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

Scalding Viper

Whenever an opponent casts a spell with mana value 3 or less, Scalding Viper deals 1 damage to that player.

Scalding Viper // Steam Clean

Ghyrson Starn, Kelermorph

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Three Autostubs — Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson Starn, Kelermorph deals 2 damage to that permanent or player.

Brainstorm

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

Lock and Load

Draw a card, then draw a card for each other instant and sorcery spell you've cast this turn.
Plot {3}{U} (You may pay {3}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Mana Leak

Counter target spell unless its controller pays {3}.

Firebrand Archer

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

Spikefield Cave

Spikefield Cave enters tapped.
{T}: Add {R}.

Spikefield Hazard

Spikefield Hazard deals 1 damage to any target. If a permanent dealt damage this way would die this turn, exile it instead.

Spikefield Hazard // Spikefield Cave

Eroded Canyon

Eroded Canyon enters tapped.
When Eroded Canyon enters, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

Thermo-Alchemist

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