The Big Picture Few franchises have such a complex lore as Dune. In Dune: Part Two, Denis Villeneuve explores many elements of the original Frank Herbert novel while also elevating some of them with original ideas. One of those is the Bene Gesserit, the ancient sisterhood that has been pulling the strings of nearly every major galactic event for millennia.
After his psychotic birthday bash, Feyd-Rautha walks through the corridors of the Harkonnen castle in Giedi Prime by himself, followed by Lady Margot. He puts a knife at her throat to ask her what she's on about, but the tables quickly turn. After playing coy at first, she quickly gets him under her control and leads him to the guest wing of the castle, where he has never been before. Feyd-Rautha is clearly out of his element, and what he does now isn't up to him anymore.
Feyd-Rautha Is the Best Alternative for the Bene Gesserit To Retain Their Power Close In Part Two, the Bene Gesserit play a larger role than in Villeneuve's first Dune movie. Reverend Mother Gaius Helen Mohiam is present for a lot of the important events, and we meet other members of their sisterhood, like Lady Fenring and Princess Irulan themselves.
Paul Atreides is aware of the Bene Gesserit's involvement in his father's death and the destruction of his house. His ascension in Arrakis puts the sisterhood in a delicate position, because it's something they hadn't foreseen. The best possible outcome to the whole Arrakis affair is Paul's crusade being defeated, which is why Feyd-Rautha became such an important puzzle piece for them. For that to happen, however, the Bene Gesserit had to find out if he could be controlled.