Sona rework concept based on Odyssey Onslaught augment effects

(P) Composer Sona's Q, W, and E all have a shared cooldown which starts at 6 seconds. The second, third, and fourth rank-ups in each of Q, W, or E reduces this shared cooldown by 0.5 seconds. Repeating the same ability in a row will grant the 'repetitive' debuff. Each stack of 'repetitive' will multiplicatively diminish effects from further repeated casts of that ability by 35% and increase its mana cost by 35%, stacking up to 5 times. Casting a different ability or pausing for 5 seconds between ability casts will remove all stacks of 'repetitive'.

Playing certain sequences of abilities will activate bonus effects [causing a distinct audio snippet to play]. Pausing for more than 5 between ability casts will cancel the sequence. R counts as a wildcard which can replace any other note to complete any of the sequences below.

E Q Q Boisterous Sona's next basic attack deals AOE magic damage

Q W W Clutch Grants a shield to the last ally healed by Aria of Perseverance

W E W Benediction Aria of Perseverance heals one extra ally

Q W E Rouse Empowers nearby allies to deal bonus damage

W W Q E W W Lullaby of the Oasis [calming and mysterious song similar to Arabesque by Debussy] Aria of Perseverance pulses for several seconds, healing nearby allies and restoring a very small amount of mana.

E W E Q E E Rise of the Typhoon [exhilarating song like Ride of the Valkyries] Song of Celerity lasts bonus time, deflects some damage from incoming ranged attacks, and grants Tenacity to Sona.

Q Q E W Q Q Ode to Destruction [dramatic song like O Fortuna] Hymn of Valor pulses, dealing damage over time in an area of effect surrounding Sona.

Note: You can chain together sequences to achieve multiple effects like (Q [W W) {R E W} W] (Clutch) [Lullaby of the Oasis] {Benediction}

The rest of Sona's kit would remain similar to current but would be heavily rebalanced with number adjustments to accommodate this new passive into her overall power budget.