Otilia is the Muse of Protection, one of the nine Muses built for the Storm King by Van Rijn. Like all the muses, Otilia was designed like her "sisters" to teach and inspire though she (or her body, at least ) proved capable enough in a fight. She originally had large wings made from cloth feathers hung on a metal frame, as depicted in the fresco of the Muses at Transylvania Polygnostic University.

Prior to the attack on Castle Heterodyne, Lucrezia Mongfish transferred Otilia's consciousness into a fleshly body, creating the construct Von Pinn. Lucrezia also transferred all or part of Castle Heterodyne's consciousness into the Muse body. Neither Otilia" nor the Castle appreciated this development.

As Von Pinn, Otilia became the nanny for Klaus Barry Heterodyne and was later employed by her former charges namesake as a caretaker for the students/hostages onboard Castle Wulfenbach. Already obligated to obey potentially conflicting orders from her creator and her King, Von Pinn was additionally compelled by Lucrezia to protect Agatha's life with her own as her new "container" was developed to obey her Mistress. Her construct body was severely injured after falling down a nearly bottomless pit while fulfilling this obligation.

The Castle/Muse was kept in the depths below The Great Movement Chamber until Agatha shut down the Castle's AI with Fra Pelagatti's Lion. It was then evidently set free , possibly having been contained by Castles own systems.

While working with Higgs to complete some apparent arcane Heterodyne proving , involving drinking the unfiltered water of The Dyne, the Castle/Muse incidentally proved instrumental to the success of the modified Si Vales Valeo procedure that cured Agatha and Tarvek of Hogfarb's Resplendent Immolation.

Unfortunately, the Muse body was rather badly damaged . However, both the Castle and Otilia eventually found more amenable bodies .

Leaning on each other

The triumphant soul of Otilia with her Heterodyne.