Settler ships are special large capacity deep space ships. They are typically colossal in size and can hold an entire colony's worth of people, but some much rarer ones come in sizes that only support a small crew.
Unlike normal deep space ships, the settler ships are rumored to be created from both organic and inorganic material. Many people report feeling watched, hearing a heartbeat or breathing, and being generally unsettled within these alien ships when not in cryo sleep. Some have even compared them to old titans, angels, and sleeping beasts, despite settler ships only ever acting as transportation across the vaster and vaster void.
The Lightbringers were the first human sect to run into the alien races already occupying and seeking out livable heat systems aboard these ships, though it is unclear which race first created them as they had already been present within the fading universe for millenias. The Lightbringers saw these ships as heralds of the end times, absorbing what believers they could from the occupants and killing all others that refused to join them.
The Lightbringers then used the technology aboard to further both their reach among the remaining stars and further perfect their weaponry. Thus did cloning technology emerge with the right set of DNA and help the Lightbringers create a blueprint for the ultimate soldier. And eventually, created a method to duplicate that clone into an unstoppable army.