I Transmigrate into a Book and Tame the Cursed Prince

She was a rookie agent who died on her very first mission, then unexpectedly transmigrated into a book her partner had written as a hobby. In the book, Shen Hanyun is the daughter of the prime minister, a vicious supporting villainess who does every manner of evil and meets a miserable end. Reborn in another's body, she is determined to turn her fate around. Evidence of the prime minister's crimes is being rushed to the imperial capital at top speed. Unwilling to intercept an urgent courier, Shen Hanyun finds another way. Through her own efforts, she changes the prime minister's family's sentence from execution of three generations to exile in Lingnan. When the Marquis's household gets wind of the news, they weigh their options and swiftly cut ties with the prime minister's family. Break off the engagement? Hmph! Shen Hanyun couldn't be happier. Her hypocritical father-in-law, vicious mother-in-law, and fiancé have been carrying on with the heroine without a matchmaker. Breaking off the engagement is exactly the right way for her to cut her losses. After ending her engagement to the Marquis's household, she makes a show of marrying into the Prince Duan's household in Lingnan. Prince Duan, Lu Shuyu, is a prince who bears his mother's surname. His achievements in war overshadow the throne, and he is the only prince able to command the army without a military seal. At the height of his power, he never seized control of the court. Instead, he retired to Lingnan to live as an idle prince. In Lingnan, his former fame as a battlefield commander has faded, replaced by a reputation for bringing death to his wives. He marries four consorts in a year, and on the road to each wedding, he kills without restraint. A grand bridal procession stretches for miles, with the wedding sedan at the front and a coffin bringing up the rear. At the wedding ceremony, Lu Shuyu wears mourning clothes, noble and aloof. Shen Hanyun wears bridal red, striking and flamboyant. On their wedding night: "My fate brings death to my wives," Lu Shuyu says. "What a coincidence. Before I was born, my grandfather had my fortune told. They said I was destined to bring my husband good fortune," Shen Hanyun replies.