Cleo is Sanctuary's go-to artisan when it comes to masks—she's basically the backbone of their mask-making operation. The Grand Master calls her "the mask-artist maestro," which is both a title and a pretty accurate description of what she does.
Beyond the craftsmanship, she's also documented Sanctuary's entire history, making her one of the most reliable sources on how the place came to be. Fans and scholars alike tend to turn to her whenever they need to know what actually happened back in the day.
Content compiled by AnimeList.moe from publicly available sources.
