Kassen
A member of Eiattu's Royal Family, specifically a princess, Kassen was the offspring of Emperor Uthorrferrell Cartha and the older sibling of Isplourrdacartha Estillo; she was killed alongside the other royals by Eiattuan nobles in a rebellion.
Behind the scenes
The Eiattu Royal Family generally possessed extended names, often shortened for casual use. "Kassen" was probably one of these informal nicknames, preventing us from knowing the princess' complete formal name.