I think the most interesting part that is in the movies is a bit about how the power works, and how its related to the worms.
As in, it is one of the layers of the central theme of the series: Artificial processes to change the human mind and body.
That much is exposed, the change. Even in DUNC and DUNC 2 you see Paul being molded, from a boy into an hermaphrodite, and then into a new man. And so forth.
The whole story has many more layers on that subject, everything is connected in this "process". Down to an autistic level of every life form (not just the worms) of arrakis.