Cosi's Trickster

Whenever an opponent shuffles their library, you may put a +1/+1 counter on this creature.

Clever Lumimancer

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

Harmonic Prodigy

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If an ability of a Shaman or another Wizard you control triggers, that ability triggers an additional time.

Soul-Scar Mage

Prowess
If a source you control would deal noncombat damage to a creature an opponent controls, put that many -1/-1 counters on that creature instead.

Adeliz, the Cinder Wind

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