I recommend the Legend of the Blood-robed Marquis of the Qin Dynasty to you. The male protagonist is the Blood-robed Marquis Bai Yifei, and the female protagonist is also a transmigrator. Although the plot doesn't completely match the information you provided, it's still a story about the time of the Qin Dynasty. I believe you'll like it. I hope you like this fairy's recommendation. Muah ~😗