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.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

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

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Jeskai Sage

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Jeskai Sage dies, draw a card.

Quench

Counter target spell unless its controller pays {2}.

Stormchaser Mage

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

Spellweaver Eternal

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)