Martial King's Retired Life - Chapter 40Book 15:

Ji Huan’s parents both died in a traffic accident.
Unexpectedly, his older sister also meets the same fate.
Yet everything starts when he says “goodbye” for the last time.

Hunting monsters? Genetic comparison?
Ji Huan flees with his older sister’s posthumous child to his hometown, Bade Town.
The three Grandpa, grandson, and nephew all live interdependent days.
However, inside the swaddling clothes is not a human baby,
But a monster…

Black egg body, white ring eyes, red mouth.
A child, ah! Doesn’t he have two eyes and a mouth! Resembling an egg, he is Ji Huan’s cute nephew!

Vermilion tiled wall, white lotus pond, convalescent courtyard.
This entirely neatly handsome and elegant young man: Ah Jin.
However, he told Ji Huan about the secrets of the monsters and discreetly taught him.
Bade Town is also slowly being covered in monsters…

Or, the record of a small countryside monster’s growth.

- 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!

I became a professor in a game by accident. To make matters worse, I even messed up the difficulty settings. Now, I’m stuck playing on Hell Mode. A world on the brink of war with the Demon King. An Assassin Department where mu*der is legal… as long as you aren’t caught. I thought I’d have to claw my way through just to survive in this wretched place, and that was the case at first. But nowadays… “No matter how hard I try, I can’t be like you, Professor… How do you do it?” “Please… become our god.” “What do you know? What is it you know? Why do you make me want to live…?” One by one, everyone at the academy began to obsess over me.

At the end of a Dynasty filled with Demons and rampant Martial Artists, Lin Xuankong has unfortunately transmigrated to this era, becoming a poor and sickly old man. However, with the help of the system Life Plate, his Talent and Comprehension grow stronger the longer he lives.And his much younger wife is a martial master...“That iron ball used to be Zhang Wu's knife. I squeezed it a couple of times, and it ended up like this! ” said his wife.“I hope you can teach me some Cultivation Techniques. As for the reward...” said Lin eagerly.