How Did I Become The World-Destroying Evil Spirit's White Moonlight?

[Couple Playing Along with Each Other + Sweet 1v1 Romance + Small Ensemble Cast + Cultivation + Episodic Mysteries] [Sadistic Evil Spirit Youth & Innocent-Looking, Scheming Drama Queen] Qiao Ying transmigrates into a cultivation novel, becoming the ghost-marriage bride whom Cen Yunyu, the world-destroying villain, killed in his backstory. Her story begins with a ghost marriage. The evil-spirit youth crawls out of a coffin, his long sword stained with blood, and massacres everyone present. Under the bright, cold moon, the youth stands amid a mountain of corpses, dressed in red with ink-black hair. His beauty is peerless, yet he is terrifying beyond measure. When Cen Yunyu looks at her with a half-smile, Qiao Ying knows she is finished. No cheat abilities. No system. Even worse. When the sword's edge presses against her throat, she can only cling to his leg and tell an outrageous lie: “I'm your future wife!” The youth's sword veers aside. * Cen Yunyu was born an evil spirit, a living embodiment of calamity, rejected by the entire world. Everyone fears and hates him, yet no one can kill him. After being sealed by an alliance between the righteous and demonic paths, he returns to the age of eighteen. A future wife? He loved her desperately? Heh— How did he not know about any of this? * Much, much later, Qiao Ying, who has genuinely married the world-destroying evil spirit, is left bewildered: How did their fake relationship become real? “What? You don't want to?” the youth asks with a half-smile. His peach-blossom eyes are as beautiful as black jade, yet carry a bone-chilling coldness. Qiao Ying immediately throws herself at him and hugs him. “I do, I do! Just put the sword down first. Don't massacre the city!”