Giganhanjeong Gongjunim

Who wouldn't want to be a princess? You’d have maids at your beck and call, riches to indulge even your most unnecessary wants, and a dashing young prince who’d charm your socks off. But what if you became the villainess of a story? One day, Jae-eun wakes up as Sheilia Aidenrose, the notoriously cruel princess of “The Rose of Isonia.” As she knows all too well of Sheilia’s gruesome end (the novel was written by her sister, after all), Jae-eun is determined to take matters into her own hands. She won’t let Sheilia’s fate be dictated by the original novel! Little does she know that this means she’ll change the fates of all those involved, even that of the most minor characters...
(Source: Lezhin)
Note: The chapter count includes a prologue.