Chaola
Before the events of the Prelude to Dune prequel trilogy (1999–2001) by Brian Herbert and Kevin J. Anderson, Chaola Fenring (also known as Cirni) is lady-in-waiting to Habla, the fourth wife of Padishah Emperor Elrood Corrino IX, and serves as wet nurse to both her son Hasimir Fenring and Crown Prince Shaddam. It is also hinted that Chaola may have secretly been a sister to Elrood. Chaola's son Hasimir proves to be a failure for the Bene Gesserit breeding program; as Paul Atreides himself notes in Dune (1965), "Fenring was one of the might-have-beens, an almost Kwisatz Haderach, crippled by a flaw in the genetic pattern — a eunuch, his talent concentrated into furtiveness and inner seclusion." Nonetheless, the bloodline manipulations of the Bene Gesserit produce a supremely intelligent and perceptive killer in Fenring, who later serves as Emperor Shaddam's chief counselor.
Read more about this topic: List Of Dune Bene Gesserit