A mysterious young astrologer who proclaims herself to be "Astrologist Mona Megistus," and who possesses abilities to match the title. Erudite, but prideful. Though she is often strapped for cash and lives a life of thrift, she is resolved to never use astrology for profit... It is this very resolution that has caused her to constantly fret about money. Mona has settled in Mondstadt to avoid suffering the ire of her master after unwittingly reading the latter's diary.