DxD: Building A Demon Clan From Scratch. - Chapter 166: Chuunibyou?

I started off as nothing, just a mass of consciousness that slowly evolved. Just your average overpowered existence hungry for a multiverse adventure.

To treat her sick brother, she was forced to marry him in place of her cousin, who was disfigured and paralyzed. At first, their relationship was purely transactional, with neither caring much for the other. But after going through a lot together, they fell in love with each other. He doted on her deeply.She was considered an ordinary person by the world, but it was later discovered that she had multiple identities - a mysterious underground boxing champion, a highly-skilled doctor, and a mysterious and renowned composer... He also realized that their fates had been intertwined long before they met.

their example, leading to continuous warfare! However, the aboriginal people of this otherworld who have been blinded by the aesthetics of violence! Rightnow! And in the future! Let me teach you what kind of mecha represents the romance of a man! Let me show you what kind of propulsion is the iron torrent! Let me instruct you what kind of weapon is the deterrence for peace (implied by “nuclear” here)! Let me! Teach you! What exactly is the air-to-ground cluster offensive and the all-round air, sea, and land strike!! Gentlemen! I, indeed, love war! But what I love even more is to stop war with war and bring about a prosperous future where the whole world is unified for thousands of generations! Unite all nations and subdue all races! When the whole world is united as one, it will last forever...

In the early world of immortal cultivation, there was no physical cultivation among immortal cultivators. And a top bodybuilder who came from the earth has opened up a new path here and became the ancestor of physical training.

- Description from novelbuddy