Rakuin no Monshou - Volume 4, Chapter 1: Dark Clouds over Apta

Xiao Ze, who was dedicated to the people and vowed to become a generation of Ming Jun, accidentally fell on a little lady.
The little lady was born beautiful and lovable.
So Xiao Ze accepted his life and got the name of fear.

ps:
①The male protagonist has no concubine, and he is dedicated to serving the country.

- Description from novelbuddy

The Imperial Court of Tang Empire became dim and corrupt. The Emperor believed eunuchs. The officials vied with each other for authority. The Tang Empire was about to collapse. The flouring Confucianism, Buddhism and Taoism eyed it covetously. The three sects wanted to contend for the domination of the whole world. Which one would win in the end? Or would they coexist peacefully at last? Armies of different nations invaded the frontier on all sides. People and the whole world were in extreme misery. Who could save them?

A young man of the Imperial Clan was reborn in Chang’an. In the Last Life, he was framed and was driven out of his place. He was the king of the subjugated country. When he wandered on the streets, he wanted to be an ordinary people and live an ordinary life in Chang’an but failed.

In this life, he determined to fight against the heaven and change his own fate. He would not give those people an opportunity who framed him in his Last Life. He would hold his title and his place. In order to maintain order and peace of the world, he was going to wipe out all villains of the whole world with the Imperial Sword, adhere to the emperor’s principle, and enact the new national law. He would rule over the empire to prove himself.

- Description from Novelupdates

To be exact, the female lead is an “older sister” type, amid many beauties and handsome guys, she's no white lotus.Also, it's said that the name of this book is the same as a brand of sheep's milk powder.

Elias' world was destroyed right in front of his eyes. Only after his transmigration did he learn that there was nothing natural about its destruction.“Mother, I passed my Practical Exams! I was so lucky to get a weak world like Earth for my practicals! It only took a few months!”The person who destroyed his world was the eldest son of the family he was transmigrated to, the Ashborns.He could never forget his sister's cries when she suffered and eventually died from the virus that wreaked havoc in his world. And here he was, the person responsible, laughing.Elias wanted to repay the favor. He wanted to bring absolute ruination to these people. And for that, he had to play by their rules. He had to become the Architect of an Apocalypse…