Mask of Rull

My planet was dead. The sky poisoned by war with an extrasolar enemy in a war that continued to rage. Then Calus came. —Rull, Gun of Kaga Clipse

The Clipse had only celebrated their first century of global peace when the cataclysm struck. A flash of interstellar gamma radiation killed every living thing in their western hemisphere, poisoned the atmosphere, and destroyed all technological civilization.

As the surviving Clipse clawed back to subsistence cave farming, they met a new horror. The radiation had burnt a mysterious signal into the comets and asteroids of their system, and as this debris rained down on their world, it seeded hideous alien life.

Millennia later, they had become a civilization that knew only war—a culture that revered the gun, batteries of planetary defense weapons holding back an endless poison sky-fall. The moon Kaga-Clipse bristled with interceptors, ready to fend off any threat. They were no match for the Leviathan.