This is how Palpatine returned in The Rise Of Skywalker | Star Wars Lore

Hello Hello, and welcome to today’s video! The Empire had several off the record projects, so off the record that only the highest ranking officials within the Empire such as a select few Grand moffs, or Grand Admirals, would ever know of them. One such project named Project Necromancer would threaten to cement the course of galactic history for generations.. The Advanced Science division of the Empire was a highly clandestine research division organized under the Imperial Science Bureau and responsible for the conduction of advanced biological research. Requested by Emperor Palpatine himself, Chief Scientist Royce Hemlock was enlisted to ensure Project Necromancer was completed. With Palpatine stating that the success of this rather elusive project would be essential to the longevity of the Galactic Empire. Promising Hemlock all the resources required to achieve fruitful results. Before we take a deeper look at this scientific endeavor, if papa palps has shown us anything throughout Star Wars lore its that whenever there's something that interests him, not only is he going to do everything he can to make it a reality but… it’s never a good thing, and likely has some sort of consequential twist to it, a twist which will start to make itself more apparent as we cover the project. Project Necromancer was a biological clone research program headed by Dr. Royce Hemlock with the goal of achieving a successful M-count replication throughout the cloning process. The trouble with the project came from ensuring that the M-count wouldn’t diminish during the cloning process. Project Necromancer was at extreme risk when its most important asset Omega, a clone of Kaminoan origin, proved to be the only clone with DNA that showed to be a successful binder.