Codenamed "Marionette", Sandrone is a Fontainian researcher for the Fatui who modified and worked with Automatons. She is always engrossed in her research on Automatons. Sandrone does not have a particularly friendly personality, as she always treats others with impatience or even outright contempt. Sandrone was engrossed in researching automatons left behind from the fall of the nation of Khaenri'ah, going as far as to modify them for her own use.