Electrostatic Field

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

Fiery Inscription

When Fiery Inscription enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, Fiery Inscription deals 2 damage to each opponent.

Guttersnipe

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

Young Pyromancer

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

Judith, Carnage Connoisseur

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this creature dies, it deals 2 damage to each opponent."

Rockslide Sorcerer

Whenever you cast an instant, sorcery, or Wizard spell, Rockslide Sorcerer deals 1 damage to any target.

Erebor Flamesmith

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

Thermo-Alchemist

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

Seething Song

Firebrand Archer

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

Kessig Flamebreather

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

Dark Ritual

Mana Geyser

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

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.