Lane poke, trading, and teamfight heal/shield scaling.
Empowered abilities and resource manipulation
Your attacks and abilities send Aery to a target, damaging or shielding allies.
Hitting enemy champions with a spell grants maximum mana.
After reaching 250 mana, Manaflow Band restores 1% of your missing mana every 5 seconds.
All movement Speed bonuses are 8% more effective on you.
Your first ability hit every 20s burns champions.
Durability and crowd control
After taking damage from an enemy champion, the next 3 spells or attacks you receive deal less damage.
Heals and shields are 5% stronger and increased by an additional 10% on targets below 40% health.
+6 AD or 10 AP
Summon Aery is a great option for Sona both offensively (with autos and [Q]) and defensively (with [W]).
Manaflow Band is a great option here for Sona because you're going to want to play aggressively in lane early spamming [Q].
Celerity's bonus Movement Speed is great to for helping you to position better in teamfights so that you aren't quickly dying from your low health pool.
Scorch allows you to dominate the lane phase if you're able to consistently poke with your [Q].
Bone Plating on Sona provides fantastic early-game mitigation so that you're able to take good trades with [Q] poke and an empowered Auto Attack.
Revitalize synergizes extremely well with Sona's [W] especially heading into the mid to late game when you've built a few extra heal/shield items.