Thermo-Alchemist

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

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.

Storm Entity

Haste
Storm Entity enters with a +1/+1 counter on it for each other spell cast this turn.

A-Sorcerer Class

(Gain the next level as a sorcery to add its ability.)
When Sorcerer Class enters, draw two cards, then discard two cards.
{U}{R}: Level 2
Creatures you control have "{T}: Add {U} or {R}. Spend this mana only to cast an instant or sorcery spell or to gain a Class level."
{1}{U}{R}: Level 3
Whenever you cast an instant or sorcery spell, that spell deals damage to each opponent equal to the number of instant and sorcery spells you've cast this turn.

Curiosity

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

Firebrand Archer

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

Galvanic Relay

Exile the top card of your library. During your next turn, you may play that card.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Guttersnipe

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

Don't Try This at Home

If a hot source you control would deal damage to a permanent or player, it deals that much damage plus 1 instead. (Something is hot if it has hot things in its art, like fire or explosions.)
{1}{R}, Sacrifice Don't Try This at Home: It deals damage equal to twice the number of hot cards in your graveyard to target creature or planeswalker.

Conductive Current

Conductive Current deals 3 damage to each creature. Choose an instant or sorcery card in your hand. It perpetually gains "If this spell would deal noncombat damage to a permanent or player, it deals that much damage plus 2 instead."

Snow-Covered Mountain

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Ral, Storm Conduit

Whenever you cast or copy an instant or sorcery spell, Ral, Storm Conduit deals 1 damage to target opponent or planeswalker.
+2: Scry 1.
−2: When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Frantic Search

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

Kessig Flamebreather

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

Ground Rift

Target creature without flying can't block this turn.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Snow-Covered 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.)

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Electrostatic Field

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

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Crow Storm

Create a 1/2 blue Bird creature token with flying named Storm Crow.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

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.)

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.