Toradora! - Volume 7, Chapter 4

Unhindered in the Demon Domain, the king is solitary!

In the world where immortals and demons strive, a good natured fellow sought the Demon Dao in search of justice.

At the end of his journey, he had eventually become this generation’s Heavenly Demon Emperor.

Although I am not fond of slaughter, I do not dislike it!

Desiring to see the Demon World, this is how I strive, this is how I become the Peerless Demonic Lord!

- Description from Novelupdates

At first, when he learned that he was forced to go to many different routine worlds and be reborn into all kinds of cannon fodder, he was against it.

Senior high school student Dugu Hong was logical autistic and had a very high IQ. Despite his impressive IQ, he was never taken seriously by his teachers or schoolmates. While playing a recently released eastern Wuxia online game called Jiang Hu, three vicious classmates trapped Dugu into a mountain cave in the game with no hope of escape unless he deleted his account and re-register it. Not succumbing to their demands, Dugu decided to stay in the cave and explore the game system, which benefited him greatly. His persistence to obtain massive internal strength aided him in finding a superior way to improve himself, and thus opened the function of inner observation of the main and collateral channels. Meanwhile, in the real world, he discovered he had supernatural powers when he tried to save the girl he secretly loved who had caught the eye of a gangster on the suburban railway.

Over a million years ago, the first human contracted with the first Spirit. Ever since then, Spirit use has become commonplace. Humans used Spirits to carry items and start fires. Eventually, even start wars. Thousands upon thousands of years past and one day, one human did the impossible. He transcended his mortality and ascended to the realm above.