My Sister the Heroine, and I the Villainess - Chapter 66

There was a man in the modern world that built his business empire from scratch. He was hailed as a genius by his peers and was respected worldwide due to his contributions to the world.If it is not only for that unfortunate accident that led to his death. He was a man who could potentially change the world with his mind that still stores a plethora of ideas.But—fate had others plan with him. He found himself in another world, what’s more, it’s primitive and technologically backwards compared to his last world. And what’s more, he turned into his younger self, and in this world, he was an orphaned boy.For him to survive, he must use everything that he had at his disposal, and that was all in his head.

"The boy has no powers," they claimed.

Su Yan adored Xie Yu for many years and finally got what she wanted, but Xie Yu ran away on the wedding day, making her a laughing stock. At that time, Bai Xingfan appeared in front of her. He held a black umbrella in his skeletal hand to shield her from the heavy rain, and the other hand stretched out in front of her with a gentle and determined voice: “Don’t be afraid, still With me.” Su Yan was stunned with tears in her eyes for a long time, and finally, she reached out to Bai Xingfan.

- Description from Novelupdates

Xu Mo, a modern high school student was sent back in time to Jing Kingdom and found herself trapped inside of the body of a princess with the same name.

She had barely recovered when she learned of an unparalleled fiancé and in a daze, they got married. Then the stunning genius physician who normally does not pay attention clamoured to marry her. After that, there was a cold general, a flirtatious lord, a tsundere young master……

As it turns out, this was a male-dominated dynasty. Because the female population was sparse, the entire nation shared wives regardless of rank or nobility. Is it feasible for someone who wants to maintain monogamy in this dynasty?

- Description from Novelupdates