7th Demon Prince Jilbagias' Chronicle of Demon Kingdom Toppling - Chapter 29: The Demon King’s Children

As a top cultivator in the Canglang Realm, Fang Mu has been a little troubled recently.

Because his new apprentice seems to be a little brainless.

…

Brain-disabled apprentice: “Master, the GM you killed is dead!”

Fang Mu: “Nonsense, people are killed and still not dead?”

Brain-disabled apprentice: “No, I mean, he died in the real world!”

Fang Mu: “Isn’t this the reality?”

The brain-dead apprentice “Of course not, you are just an NPC in the game!!!”

Fang Mu: “…”

…

Brain-disabled apprentice: “By the way, master, the last time it was a closed beta test, how come you haven’t been recalled?”

Fang Mu: “Oh, there was indeed a time travel back in the first two months.

But here I was blocked. ”

Brain-disabled apprentice: “Master, you are a bug…”

“Um?”

“Master, you will be corrected by GM with code!”

- Description from novelbuddy

Born into a wealthy family, Gu Shenwei was spoiled and carefree. However, at the age of 14, his entire family were brutally murdered, and he was caught by some bandits who sold him into slavery. As a slave boy, he entered Golden Roc Fort by chance and found the man who had slaughtered his family. He endured insults and worked hard to improve his kung fu while working as a slave boy. He learned from and plotted against his enemy under the enemy’s nose. He became increasingly ambitious as he became more and more powerful. He would only be satisfied if he completely destroyed his enemy—by fair means or foul. Gradually his bitter experience turned him into a totally different person.

Arthur got randomly transported to another world. Some people would find that terrifying, but not for him, who was tired of his old life; it was an opportunity.

And, after having bad luck all his life, the tide changed.

It was a world of magic where wizards fought side-by-side with their familiars. Arthur got summoned to be one of these so-called familiars.

He was furious. The thought of becoming a pet was not something he liked. Well, that changed when he saw who his master was.

A hot-woman. And, to make everything better, Arthur was inside the Frostpeak Magic Academy, which only had women students.

“This is heaven. All familiars are beasts, but I'm different. I'm a good-looking man inside a place filled with hot girls.”

When he thought his luck could not get better, he unlocked a system that helped him with everything. Of course, he used the system for a greater good, like getting girls.

A tree of 10,000 flowers, the world is the door.
The spells change a lot, but the hearts of the people are unchanged.

- Description from Uukanshu translation