MTL - The Demon King Always Thinks I’m Secretly In Love With Him - Chapter 10

After ten thousand years of cultivation, he could have achieved immortality. However, his lack of human experience led to his failure to attain immortality.Thus, he resolved to immerse himself in a century of human existence, seeking to enhance his journey toward immortality. What he didn’t anticipate, though, was that upon entering the human world, he would find himself cast as a son-in-law, facing disdain not only from his wife’s parents but also from his beautiful wife herself.Armed with a wealth of cultivation knowledge, how could he transform his drab human life?

Growing up in poverty, Sunny never expected anything good from life. However, even he did not anticipate being chosen by the Nightmare Spell and becoming one of the Awakened - an elite group of people gifted with supernatural powers. Transported into a ruined magical world, he found himself facing against terrible monsters - and other Awakened - in a deadly battle of survival.
What's worse, the divine power he received happened to possess a small, but potentially fatal side effect...

“Brother Katakuri, I’m sorry, I don’t want to bear the name of Charlotte for a long time!”

“Ace, your flame is too weak!”

“Akainu, magma is dessert to fire dragons! Why don’t you understand this?”

The man who ate the dragon fruit, the traitor of the Charlotte family, sprinted towards the title of One Piece!

- Description from novelbuddy

Medieval times, warring knights, dragons, demons, gods, pirates, behemoths...Barbaric, ignorant, backward, numb, starvation widespread, people unable to make a living...Damn it! Punch to explode this era!!Reclaiming wilderness, farming, bridge building, road paving, coal mining, excavating minerals!Leveling up, recruiting apostles, forging an army!Barrage troops! Pushing horizontally!Quack! My steel torrent is invincible in this world!!Roman: “I am your destiny! Kneel before me!”So, you were supposed to farm, but somehow you ended up establishing a vast empire and becoming the emperor?