MTL - Book of Technology - Chapter 437 deal with

Known as the country’s top onmyoji, Yuuma Kisaragi, who lived to the age of 99, awoke to find himself in an unfamiliar forest. A voice echoed in his mind, revealing that he had been reincarnated into another world at the age of 20.“Good morning, Master. Skip the greetings and please defeat the goblin in front of you.”The voice belonged to a skill acquired during reincarnation called “AI,” designed to assist Yuuma in his new life. When the skill, AI, took over the form of a golden-haired fox yokai, the familiar shape of Yuuma’s shikigami, he decided to embark on a new life alongside AI-chan.The onmyoji and AI-chan’s second life began, tackling various challenges and formidable enemies with the strongest spells and shikigami.

The war of gods left the earth no winners, but a broken world.

He lived from BC to the Middle Ages, from the Renaissance to the Industrial Revolution, and from Cyberpunk to the Interstellar Age. He has been a king and a prophet, a knight and a nobleman, a versatile artist, a genius inventor…
This is a four-thousand-year human epic——
“To us four thousand years from now:
“Is the world at peace? Is famine extinct? Can people touch the stars? How long is the human lifespan? How far is the boundary of the earth? Human…do you remember us?”
——Excavated from Earth Age Tenth Century BC, Solomon Prayer Book.

- Description from novelbuddy

Xia Mi found himself transported into a classic JRPG game, becoming a villager in a beginner's village.His biggest wish was to save money and marry a woman from a different race as his wife, live a peaceful and worry-free life, and eventually pass away peacefully.One day, the heroes defeated the Demon King.[Name: Xia Mi][Profession: Villager]New addition: [Profession: Successor to the Demon King]“Quickly take action, Demon King! Kill all the heroes! Restore the glory of the demon race!”Wait, did something go wrong here?In the beginner's village, where Xia Mi spent his days farming and serving as a passer-by, he suddenly had an identity panel.But he was just a villager in the beginner's village!“Where is the Demon King? Where is the Demon King?”News of the Demon King's emergence spread across the continent, and every hero who came here to defeat the Demon King could see a constant stream of monsters in the beginner's village, but never caught sight of the Demon King.A villager from the beginner's village: Demon King? I'm just a villager. I have no idea what it is.