ノネット・エニアグラム

A PS2/PSP only original character. Nonette Enneagram is the Knight of Nine. She attended military school with Second Princess Cornelia, who considers Nonette her senior. An upbeat and cheerful woman, she is one of the few people Cornelia actually fears. Her first and last names contain the Latin and Greek prefixes for 9, non- and ennea- respectively. Her last name may also be a reference to the Enneagram of Personality. 

From url=https://en.wikipedia.org/wiki/List_of_Code_Geass_characters#Knights_of_the_Round.