Clever Lumimancer

Magecraft — Whenever you cast or copy an instant or sorcery spell, Clever Lumimancer gets +2/+2 until end of turn.

Monastery Mentor

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, create a 1/1 white Monk creature token with prowess.

Brave the Elements

Choose a color. White creatures you control gain protection from the chosen color until end of turn.

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Arrester's Zeal

Target creature gets +2/+2 until end of turn.
Addendum — If you cast this spell during your main phase, that creature gains flying until end of turn.

Defiant Strike

Target creature gets +1/+0 until end of turn.
Draw a card.

Seeker of the Way

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, Seeker of the Way gains lifelink until end of turn.

Leonin Lightscribe

Magecraft — Whenever you cast or copy an instant or sorcery spell, creatures you control get +1/+1 until end of turn.