The Ghost-Devourer is a mythical creature so rare that even Li Qiye had never seen one before finding its prison. It was created as a heaven's punishment when an existence tried and failed to create life. It was made from that existence own ribs. Because of its creation as a punishment it was both murderous and bloodthirsty but luckily the Ghost-Devourer Lock, a lock capable of restraining and weakening it, was also created from the punishment. However at some point the lock was lost and the Ghost-Devourer escaped at that time, countless people died, creating flowing rivers of blood and mountains of corpses and the Ghost Immortal Race was nearly eradicated. Eventually, that existence caught the devourer after many earth-shaking events. After capturing it, that existence imprisoned it in the hundredth Lost mythical island of the Thousand Islands surrounded by ninety-nine Primal Ghost-Cannons.
Li Qiye found and freed the Ghost-Devourer while pacifying it with the Lock.