He Kills, She Finishes Them Off, and the Mad Marquis Is Stunned

[A dazzling, flirtatious, genuinely useless villainess transmigrates into a book] VS [A ruthless, scheming, fake invalid, reborn young Marquis with little time to live] Li Siwan transmigrates into a book and becomes a minor villain who dies in the preface. Why the preface? Because the main story takes place ten years after her death. In other words, she never got to take advantage of the golden finger of having the plot in her hands, and she is about to face a gruesome death in prison. To save her own skin, she clings to the leg of the young Marquis, another expendable character who dies in the preface. But who could have guessed that the sickly young Marquis, barely mentioned in the book, would turn out to be a scheming, ruthless man who rises step by step to the peak of power and changes his fate? From then on, Li Siwan enjoys both wealth and beauty, thriving in every way. The young Marquis, who was supposed to die young, also lives to a ripe old age. But the more time passes, the more Li Siwan feels that something is off. This young Marquis seems to have the plot in his hands...