Rosaria is a sister of the Church of Favonius. She is known for her sharp, cold words and manner. She often works alone. Despite her position in the church, Rosaria is the least devout; she is always guaranteed to skip all church activities when possible and the first one to leave if she is forced to attend. Secretly, she acts as a purveyor of justice for the Church, investigating potential threats to Mondstadt and eliminating them if necessary.