Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 471

Imperial soldier Suldak Helansa joined the infantry regiment of the Grand Duke Newman in Bena province, participated in the Warsaw plane war, and rescued a young man in the forest battle. This qualified young man suffered some injuries. Injured, still a mute, Suldak brought him into the barracks, and what we are telling is the story of this young man of unknown origin…

- Description from novelbuddy

When he woke up, Zhou Sui became a low-level Qi refiner in the world of immortality. Fortunately, he obtained the most precious Gu god bowl, which can refine various Gu insects.

Refining the Spring and Autumn Gu can prolong life and make you immortal.

The refining golden cicada Gu can give birth to dead people, flesh and white bones.

Refining the Dragon Elephant Gu to gain the power of the Dragon Elephant, the body of the Dragon Elephant, and the indestructibility of the King Kong

But the Gu he refined for the first time was the Infatuation Gu.

From then on, he discovered a bright road to cultivation.

The years change, the mountains and rivers change, but I am the eternal Zhou family.

- Description from novelbuddy

The protagonist, Punk, is a cautious, cold-blooded, and ruthless Mage.

His goal is always his top priority, over feelings or morality. When unnecessary, he doesn’t like to act like pigs to eat tigers; there are almost no life and death struggles, sometimes risky but steady progress. No strong enemy everywhere, Instead, Punk is always a strong enemy of others.

And he has a very keen interest in the secrets and teachings of the Netheril civilization.

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!