Maoyuu Maou Yuusha - Volume 4 Chapter 1, “The Rainbow is Dipping.”

In China’s modern martial arts society, Wu Xinghe was history’s youngest grandmaster of martial arts. He was invincible. Because of a strange incident, he was reincarnated as Qin Wushuang, a poor aristocratic boy in an entirely different world with its own set of rules. With his strong will and passion, he began his journey to pursue the highest peak of martial arts!

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

The Third Miss of the Qin Clan is a useless and timid person. When the Prince withdraws from her marriage, she commits suicide by jumping into the river. In the 21st century, Qin Chu, a genius agent, is framed and his soul crosses over to the Third Miss of the Qin Clan. So what if she’s useless,

“Great Mr. Chen Yu, you were successfully elected as the leader of the human race last night. Is there anything you would like to say to the world?”Chen Yu, bewildered, woke up and hadn't even put on his clothes yet. He replied, “I have no idea, I just woke up...”