Side Character Transmigration : I Became a Stray Cat!?

Yun Xi Transmigrated in a world of novels where she turned into a Supporting Villain Character who was the Female Lead’s sister-in-law, and will die at the hands of her husband who was Female Lead's brother and the Male Lead, Female Lead's husband. Because she did all the harm to the Female Lead that caused her to have nightmares. After transmigrating, the first thing she did was to get divorce from Female Lead's brother who had a sister complex. Yun Xi signed the divorce paper happily as she bid goodbye to everyone and thought she would live her own life as she pleased. But wasn’t she supposed to live her life happily from now on? Why the hell there an Apocalypse started all of a sudden? Wasn't this book world supposed to be only in the Romance genre? When did it turn into a Supernatural one? And Why did she turn into a stray cat and get picked up by her ex-husband again! "No! You let me go! I wanna go home!" Yun Xi tried to scratch him and flee to wherever her eyes went. But the guy looked at her with bloodshot eyes as he said with an aggrieved voice, "My wife left me, and now you also want to leave me? How can you be so heartless, little kitten?" Yun Xi, "..."