One Piece: Madness of Regret - Chapter 18: Bugger(1)

The Imperial Court of Tang Empire became dim and corrupt. The Emperor believed eunuchs. The officials vied with each other for authority. The Tang Empire was about to collapse. The flouring Confucianism, Buddhism and Taoism eyed it covetously. The three sects wanted to contend for the domination of the whole world. Which one would win in the end? Or would they coexist peacefully at last? Armies of different nations invaded the frontier on all sides. People and the whole world were in extreme misery. Who could save them?

The most precious things in the world are priceless. Ordinary men tend to turn a blind eye to this fact. Apart from the treasured air, sunlight, and familial love, there is still one more thing that’s extremely valuable. It’s right beside you and can be easily obtained.

- Description from Novelupdates

Having transmigrated to a new world and becoming an ordinary Blacksmith in a Blacksmith Shop, Ye Feng shortly has the Master Blacksmith System activated.