Viola is Mage's music teacher, who also acts as a mother figure towards Mage. She helps Mage embrace her low, operatic voice, as well as defy her parents, who had been hoping their beautiful daughter would be a coloratura soprano to match her delicate appearance. She also helps care for Mage in ways her parents never even try to. For example, whenever Mage’s parents deny she's ill and force her to go to her music lesson regardless, Viola notices right away that something is wrong and allows the frail girl to rest on her sofa for the entire lesson while she makes her tea. In general, Viola greatly helps Mage’s self-esteem, well-being, and confidence. Mage would easily trust Viola with her life.

I imagine Viola with a calm, motherly tone, perhaps sounding a bit like a deeper version of Princess Cadance from My Little Pony. She might have an English accent. However, feel free to improvise with her voice, I'm not very picky about her voice compared to most of the other characters!