What is the plural of Kiasyd

Pascal wrote:

Ventrue, Tremere, Brujah, Giovanni (which has already a plural ending), Nosferatu, .. are the name of the breeder, and are used as qualifiers. "Ventrue" == "Ventrue vampire", hence the plural: "Ventrue vampires".

Ventrue, Nosferatu, and maybe Brujah does not share the name of their progenitor IIRC (Veddartha, Absimiliard, and ... a lot of hypothesis including Ilyes and Troile).