Umara Mystic

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

Burning Prophet

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

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.

Stormchaser Mage

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

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.

Electrostatic Infantry

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

Dreadhorde Arcanist

Trample
Whenever Dreadhorde Arcanist attacks, you may cast target instant or sorcery card with mana value less than or equal to Dreadhorde Arcanist's power from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Naru Meha, Master Wizard

Flash
When Naru Meha, Master Wizard enters, copy target instant or sorcery spell you control. You may choose new targets for the copy.
Other Wizards you control get +1/+1.

Goblin Electromancer

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

Adeliz, the Cinder Wind

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