Damn it, I'm surrounded by childhood sweethearts - Chapter 666 - 458. Join the Organization

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.

In all my life, I’ve only made two mistakes that I regret. The first was filling out my entrance exam application wrong, and the second was offending Zhong Yuan. If I had to use an idiom to describe the impact of my mistake, it would be simply, ‘Life is no better than death’. And if I had to use an idiom to describe Zhong Yuan’s offenses to me, it would be simply, ‘Too many crimes to record’. And yet, for as evil and wicked as he was, he attracted girls the way that flowers attracted bees and butterflies.

It happened that one day, for some reason, I taunted Zhong Yuan, “The King of Hell sent you to torture some more people, didn’t he?” Without a change in expression, he replied, “In order to torture fewer people, I decided to just choose one person to torture for the rest of my life.” I asked him, “What do you mean?” He smiled at me and answered, “If you don’t go to hell, who will?”

- Description from Novelupdates

Karl Wagner is a disgruntled middle-aged instructor at the Bundeswehr Command and Staff College. He finds himself concerned about the direction which the German nation is headed in—just as he is killed by a terrorist attack. Only to awaken and find himself reborn as an infant, Bruno von Zehntner, the youngest son of a noble family renowned for its part in the German war industry a few years after the founding of the German Empire. Bruno, as he is now known, desires to rewrite history and ensure the German Empire emerges victorious in the coming century. And in doing so, finds himself entrenched in a world filled with Blood and Iron!

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.