After I Maxed All My Weapon Proficiencies - Chapter 71 - Rewards Obtained?! Upgrading Through Hacking?

What are you going to do when you pass through another world?

Yalin(MC): Perhaps, many of those seniors who passed through another world would like to use violence to solve their problems, but I like to control the fate of a country with economics and races with faith, I use benefits to instigate others so that I profit, and even making them take risk for me without them even knowing. In each country the highest is the king and behind the king is a string that is attach to my hand, for I am their puppeteer.

Yalin(MC): Certainly the credit does not only belong to me, I must give my thanks to the great knights and their leader Zero(Code Geass). The supreme master of blood, the moon princess(Tsukihime), the black and white princess, and also my ‘good friend’ called by his title the ‘God’s left eye’, president of the neutral autonomous city. Finally I must give thanks to my loyal and competent subordinates!

- Description from Novelupdates

This is a world where science and magic coexist.

Some people here seek powerful magic, and some seek eternal truth.

A science tyrant who came from another world, started as a little librarian, with magic in his left hand and truth in his right, kicking the door of the new century with one kick.

Some people call him the forerunner of magic, some say he is the founder of science.

Some people describe him that way.

In the new century, Blair is a symbol of evil.

- Description from novelbuddy

Freshman orientation season.As a third-year senior, Xiao Fei regularly comes to the school gate to welcome new students.Unexpectedly, he accidentally runs into the new goddess teacher, Tang Yuxin, and discovers that she is actually the girl with whom he spent a night in a hotel a year ago.What surprises Xiao Fei even more is that Tang Yuxin is pregnant with his child.And not just one child—three!Thus, the two begin a shameless cohabitation life right under the eyes of the students…

Seven years ago, after their breakup, he disappeared without a trace.