Path of the Berserker - Chapter 9Book 4:

A Japanese salary man was reincarnated in a different world with swords and magic. He reincarnated into the family of a powerful noble. One day when he became twelve years old, he was suddenly summoned by his father.

「 I do not mind whether it is a woman in the town or a maid in our house, learn about women.」

Having gained the permission of his father, he uses his power as a noble to have his way with women.

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Kira was living the life that others could only dream about. He was gorgeous, rich and very popular - the kind of guy that drew students from all over the place just so they could brag to others that they went to the same school as him. He was undoubtedly the number one heartthrob that every girl dreamed about.

Five years ago, she replaced her twin sister to marry him who was burned beyond recognition and even became a eunuch. Five years later, when they met again, he pressed her against the wall in the corner A low voice sounded with doubt. "Is your daughter mine? " The corners of her mouth curled into a sneer. "Are you sure you have the ability to do that? " His originally cold face instantly turned into the darkness before the storm His voice was fierce and low as he growled, "woman, you are challenging me! "