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.
Spread out when you see Sona so she can't make your entire team dance.
Kill Sona first, as she will heal up her team if left alone for too long.