Faustus Heterodyne is one of the Old Heterodynes, and thus one of Agatha's ruthless ancestors. He discovered how to spin a powerful energy out of the waters of the River Dyne, and used it to create a series of inventions the like of which Europa had never seen. His crowning achievement was building Castle Heterodyne, and giving it his own charming personality. Since we were introduced to that mechanism after it had been mutilated beyond all reasonable means of recognition, it's hard to say how similar the Castle's behavior is to Faustus' personality. The novels, however, note that Faustus is the source of his creation's fondness for weathervanes.