Maou-sama no Machizukuri! ~Saikyou no Danjon wa Kindai Toshi~ - Volume 10 Chapter 12

She was born into a powerful family of the nobility, a blue-blooded aristocrat as capable as any man. He rose from humble origins up the military ranks, an iron-blooded knight with high ambitions. A transaction for power severed her from her childhood sweetheart. A tardy encounter was the beginning of his and her vow to meet life and death under heaven, standing shoulder to shoulder.

Political intrigue, dynastic succession struggles. He trampled through it all in the toil of becoming emperor.

Old enmities became new disputes, concerning life and death of entire families. She entered once more into the palace, changing the entire political climate of their world.

Meeting once again, they had become strangers. The peach blossom were all fallen, no more than a golden age grown cold.

- Description from Novelupdates

A failed investor from 2017 got drunk and woke up in the 1980s. China is just opening up, and the economy is blooming. There is also the dissolution of the Soviet Union, the bursting of the Dot-com bubble and other financial crisis. He used his knowledge of the future and slowly build up his empire.

In a world where fate is scripted and power determines survival, Arthur Nightingale was never meant to shine.When he awakens in the world of Saga of the Divine Swordsman, he isn’t the destined hero, the villain, or even a major side character—he’s an extra. A nobody. A mere background figure in the shadow of Lucifer Windward, the overpowered protagonist who will one day ascend beyond gods.But Arthur knows the truth.The world he now inhabits is doomed. The plot is destined for a catastrophic downfall, and the so-called “geniuses” will not be enough to stop the tide of destruction. Armed with knowledge of future events and his own will to defy fate, Arthur refuses to be just an extra.

Starting from today, I am retired. But what should I be doing? I neither have the skills, nor the mind to do business, my only advantage is this pair of hands which have taken this world. What a headache…

Note: The usage of the term “retired” here doesn’t mean retiring from old age, work etc. It’s a specific term to refer to not involving oneself in the affairs of a certain society.