Sona

Sona is a virtuoso of the stringed etwahl, speaking only through her graceful chords and vibrant arias. Her genteel manner has endeared her to the Demacian nobility, though some speculate her arresting melodies actually emanate magic—a dangerous prospect in the kingdom. Silent to outsiders but understood easily enough by close companions, Sona plucks her harmonies not only to soothe injured allies, but also to strike down unsuspecting enemies.

Source: https://universe.leagueoflegends.com/en_US/champion/sona/