MTL - 70s: Raising a Baby - Chapter 211

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

- Description from Novelupdates

my name is Vexsus but you can just call me Vex

I was a human previously like all Isekai protaganists except this time i was reborn as a monster. Join me in my adventures as i discover and explore not only my new body but also this new world i'm thrust into.

This is probably the story of a modern man who became the Seventh son of Kangxi in the Qing Dynasty. This is probably the story of how the Seventh brother Yinyou worked hard and fell in love by the way. So there is no doubt that this article is ambiguous, and it is easy to guess who the couple is.

- Description from Novelupdates