Leto II underwent this transformation to implement the Golden Path, a future he foresaw as the only way to prevent humanity's extinction. The merger granted him the longevity needed to guide humanity through thousands of years of carefully orchestrated development.

Siona's rebellion represents the culmination of Leto's breeding program to create humans invisible to prescient vision, thereby ensuring humanity's ultimate survival against forces that might seek to control or destroy it through prescience.

This book serves as a philosophical culmination of the themes introduced in the original Dune, exploring the long-term consequences of Paul Atreides' choices through his son's transformation and rule, while dramatically expanding the scope of the original's political and ecological concerns.