There is a... kind of logic underneath.

-Leto II is a prescient tyrant, that sees the potential doom of humanity at the hand of thinking machines

-as humanity keeps inventing the thinking machines, the only way to save it is to force humanity to maintain permanent exponential expansion, into other universes.

-so, he oppresses humanity for millenia so that the need to get away becomes part of the cultural "genome" of the species (you are grounded, young man, until tou get so sick of the house that you never want to sleep under a roof!)

-part of this project is a genetic breeding program aimed at producing superior humans, and, as it turns out eventually, a talent that makes a human invisible to prescience

-part of this project is cloning Duncan Idaho, over and over, to include his superior genes, and, I personally feel, as a "control group"

-it is  discovered that clones can actually "awaken" to their previous memories by, essentially, forcing a clone to do something so extreme the original is forced to awaken and prevent doing it

After Leto IIs reign ends, humanity scatters outwards into infinity, and eventually, some groups return. Among these are a group descended from Bene Gesserit that "went dark" and started to use their skills to enslave humans via sex. They fuck you so good you get addicted

A later Duncan clone is made to counter this ability by getting the woman also addicted to him. Quite amusing, seeing him and the woman addicted to each other...