If Summon Aery were an item

Soul Stone

(800) + (800) + 900 Gold Total 2500 Gold

+30 Magic Resist +8% Heal and Shield Power +100% Base Mana Regen +10% Cooldown Reduction

UNIQUE Passive - Summon Aery: Damaging an enemy champion signals Aery to dash to them, dealing 10 - 37 (based on level) (+10% AP) magic damage. Healing, shielding or buffing an ally signals Aery to dash to them, shielding them for 10 - 37 (based on level) (+5 per 25% bonus mana regen) for 2 seconds.

Aery lingers on the target for 2 seconds before flying back to you, and can not be sent out again until she returns to you.