Picked up by the Protagonist of a Tormented! MC Novel - Volume 3 Chapter 7

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

Ning Yechen used to be the Demon Lord. He singlehandedly took over the Demon Realm and attacked the Heavenly Realm. His name preceded him throughout the Six Realms. He got tired of fighting, so he quietly went into seclusion and became a happy hermit.One night, an Empress from the Heavenly Realm fell into the Mortal Realm after someone drugged her with an aphrodisiac. She inadvertently fell into his room, and they made out. After the deed, the Empress quietly left. Just when he thought he would never see her again, she showed up in front of him ten years later, bringing a child, saying it was his daughter and demanding accountability from him! “She’s your daughter. You have to be responsible for us!” Ning Yechen was stunned!

The general of the demon world possessed the body of a third-rate small time celebrity. This was the story of him coming over, determined to make preparations for the demon world’s invasion of the human world, but accidentally got mixed in with the entertainment circle instead.

Yi Tianyun woke up from a sleep, and found that he awakened this Upgrade System. Crippled meridians preventing you from cultivating? No problem! With the Crazy Upgrade System, do quests, kill monsters, devour others' Spiritual Power, or refine some Elixir Pills, inscribe great arrays, and you can gain experience!Experience Value is too low? Don't be afraid, I have Double Experience Cards, Tenfold Experience Cards! Experience Value will explode, explode, explode, and levels will rise, rise, rise!“Huh, I've leveled up again?”