The Extra's Survival: Logging into the Game Master System! - Chapter 10: [Goblin hunting!]

The handsome, noble, cold, and ruthless family heir Ignatius Leclair took a liking to the fostered girl Delphine Carter in his home.From then on, the aloof man transformed into a loyal companion, taking care of children, cooking... The entire aristocratic circle was utterly shocked, with everyone envying.Delphine Carter smiled serenely: cunning, energetic, vengeful, a different persona by day and night.[Reading Tips: 1V1, both protagonists are pure, sweet story, the heroine is beautiful.]

Back to the end of Ming Dynasty, he was reduced to a slave.

This emperor, a beggar can do it, a slave can do it, a bandit can do it, but a house slave can’t do it?

- Description from novelbuddy

This stands at the forefront of strategy guides to Life (a shitty video game)!

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