Ichiban Ushiro no Daimaou - Volume 10, Chapter 1 — The Janitor’s Frightening Trap!

The young lord of a small and weak country saves a dragon beside the sea one day.

Luo Yi, a high school dropout in his original world, was isekai’d into the world of the Witcher 3. Starting out as a weak boy named Roy in the village of Kaer, Lower Posada, he was determined to grow stronger, no matter what it took. The first step toward becoming a legend was to kill. And his first kill was… a rooster. ‘You gain 1 EXP.’ Of course, Roy had his own cheat system like all the other isekai protagonists. His first step to becoming a legend started now…

Inside the dining room.

Fangzheng: Hello, I’m on a blind date.

Sister Yu: A blind date?

Fangzheng: To make a long story short, I know you are here to deal with your parents. As long as we make it clear, we can go back to our respective homes.

Sister Yu: Do you know who I am?

Fangzheng: I don’t know much, so what do you say? Continue to photograph or?

At this time, a waiter came in and bowed awkwardly to the two of them: I’m sorry sir, I made a mistake, this is not the room you are looking for! Your blind date is next door!

Fangzheng: ….

- Description from novelbuddy

This novel is about the young master of the Du clan, Du Shaofu, who was born with crippled veins and is unable to cultivate martial arts . After finding out about his situation from the clan while returning home he got hit by a lightning and a mysterious ‘first scripture’ appears and after studying for ten years he was able to mend his crippled veins together and starts his journey to glory.