So satisfying! The Great Demon King wiped out everyone equally!

(Quick transmigration, no romance, brainless, satisfying read! Abuse of scum!) Read this satisfying read and experience the full spectrum of life! Female protagonist: Cang Lan, at a treacherous banquet, witnesses the Heavenly Emperor reshaping her immortal body for his beloved, even uniting with other immortals to seize her divine bones. Cang Lan, forced to fall into demonhood, flees to the Underworld. Suddenly, all sorts of systems come knocking, threatening and bribing her, huh?! Just then, the Great Demon King gets hungry… and a fledgling 8384 system—no strength, no level, no achievements—caught the Great Demon King's eye, prompting him to immediately form a master-servant contract. System: You're serious?! From then on, the Demon King and the Unifier begin their campaign to avenge scum across three thousand worlds. (Note: The last sentence is a separate, unrelated paragraph about a crazy Great Demon King and his...)