One Piece - I Am A Different Luffy! - Chapter 457 - 455 - Wano 10.

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

If you just stay still, you’ll get to the middle.If you try to show off how good you are at work, the tasks will only increase.By the time I realized that the absolute rule of the military also applied to the position of the crown prince, it was already too late.

Travel to the world of One Piece?

They come, the security;

Became Don Quixote Rossindi?

Forget it, it can’t be reopened;

But after realizing that he had eaten the fruit of silence, the little boy became restless.

Fruit of Silence, this is one of the devil fruits that can compete for the title of “the most useless” in the world of One Piece; it is only a little better than Chopper’s “Everyone’s Fruit · Common People’s Form”!

“Dover, you said you are a devil fruit wholesaler, why do your family eat all kinds of weird ones?”

Facing the bewildered little Dover, Rossindi patted his forehead.

“Forget it, let’s practice domineering hard.”

- Description from novelbuddy

In a monstrous post-apocalyptic setting, this is a story of how a lowly Inventor, Lance, conquered a nation governed by immoral group of Scientists called The Corporation. He grew and climbed up to the highest rank possible as a Scientist with his inventions and side businesses. Eventually, he became a weapons inventor, building weapons to two opposing sides. In doing so, Lance always crossed a dilemma. How could a nobody topple the most powerful government? How could one overcome circumstances beyond his grasp, especially in a world filled with monstrous mutations called the Abominants?