Bog Standard Isekai - Chapter 6Book 3:

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

She is a waste daughter from the Su family that couldn’t cultivate. On the day before her wedding, the Third Prince breaks off their engagement in the street. Her own sister replaces her in the marriage to the Third Prince. She became the center of gossiping in the city. In her resentment, she hits herself on the Su Family’s gate, only to become the object of other people’s ghost marriage.

After transmigrating into a SF (Science Fiction) novel and enduring cruel hardships, I ascended to the throne as the Emperor of the Galactic Empire.[Welcome to the Integrated Dimensional Community.]As the community’s Lone SF Transmigrator, I unleashed the poison of new cultures on the uncivilized primitives of the Otherworlds.-Let there be light. To judge the horde of evil, the Apostle of the Goddess sent down a Graviton Surge. Thus, in that place was light along with a massive explosion…-The Grand Duke of the North has shown great interest in your Heattech…-I, as a Namgung, am thankful for the grace akin to the vast sea provided by the Great Hero. By virtue of the Vibroblade bestowed by the Great Hero, the nefarious Demonic Cult has…It seems like these Otherworlders can’t get their sh*t together.

Holo’s life was once a series of relentless hardships—bullies at school, abusive parents, and heartbreak at the hands of those he trusted. After a failed suicide attempt, a mysterious man offers him a deal: help rehabilitate four psychopathic girls, and in return, earn ten million dollars. Desperate and naive, Holo accepts, not realizing the chaos and danger awaiting him.Each girl comes with her own dark tendencies—Trixie, a violent and feral girl who acts on impulse; Scarlet, a master manipulator who delights in breaking people down; Felicia, a dangerously seductive woman battling a sex addiction; and Eleanor, a cold, calculating girl with a desire to watch the world burn. As Holo works to bring out their humanity, the girls become obsessively devoted to him, their love transforming into something darker.