Building a Viking Empire with Modern Industry - Chapter 19: Black Rocks

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- 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.

I fell into a harem manga and became a magical girl.I just wanted to become a government employee and live a carefree life without getting involved with the main characters, but…“I love you.”The main heroine, who was supposed to confess to the protagonist, confessed to me instead.…Why?