Of the 142886 characters on Anime Characters Database, 30 are from the ova Code Geass: Nunnally in Wonderland.
Code Geass: Nightmare of Nunnally (コードギアス ナイトメア・オブ・ナナリー Kōdo Giasu: Naitomea Obu Nanarī) is a manga spinoff of Code Geass: Lelouch of the Rebellion that is set in a different universe. Though some of the basic plot points remain