Sona

Strengths

Make sure to tag your allies while Sona's auras are active, but avoid getting caught out by enemies.
Save Crescendo for the game-altering moment.
Well-timed uses of Aria of Perseverance will grant you maximum survivability.

Passive · Power Chord — Accelerando: Sona gains non-Ultimate ability haste permanently for her basic abilities as she uses her abilities well, up to a cap. Beyond that cap, further successful uses reduce her ultimate's remaining cooldown instead. Power Chord: Every few spell casts, Sona's next attack will deal bonus magic damage in addition to an additional effect based on what basic Ability Sona last activated.
Q · Hymn of Valor — Sona plays the Hymn of Valor, sends out bolts of sound, dealing magic damage to two nearby enemies, prioritizing champions and monsters. Sona gains a temporary aura that grants allies tagged by the zone bonus damage on their next attack against enemies.
W · Aria of Perseverance — Sona plays the Aria of Perseverance, sending out protective melodies, healing Sona and a nearby wounded ally. Sona gains a temporary aura that grants allies tagged by the zone a temporary shield.
E · Song of Celerity — Sona plays the Song of Celerity, granting nearby allies bonus Move Speed. Sona gains a temporary aura that grants allied champions tagged by the zone bonus Move Speed.
Ultimate · Crescendo — Sona plays her ultimate chord, stunning enemy champions and forcing them to dance and dealing magic damage to them.

A suggested 5-lane lineup built around Sona, based on hero partnerships and role synergy — not win rate.