The King of The Worlds - Volume 4: Chapter 39 - Hueco Mundo Is Ours

A man reincarnates in the body of a boy who suffered a tragedy, only to realize that he is in the world of My Hero Academia. What's even stranger is that his quirk seems to have the abilities of Nen and Haki.

There was once an immortal cultivator fighting for the fate of human beings. Unfortunately, he failed that time; but fortunately got another chance as he was reborn once more as a human, on the earth of 5,000 years ago. With a second chance, he not only would embark on the road of saving all mankind, but also would retrieve his human nature on the new journey that would last for 5,000 years.

- Description from Novelupdates

He was on his way to buy some beer to celebrate his acceptance as a civil servant when he was suddenly isekai’d by truck-kun.

Just as a gamer found an overpowered skill book called ‘Item Upgrade’ in the hottest virtual reality role-playing game on Earth, something happened to the game’s system, causing his soul to leave his body and go to another dimension. Common sense dictates that he would be born anew then become the greatest overlord of this world by making use of his advanced knowledge. Not in this case! He was already dead. Only some fragments of his soul and that skill book managed to get into that dimension and merge with an ordinary common youngster called Bai Yunfei.

This was the enormous Tianhun continent, where humans could be said to have no limits. There was a group of humans here who could cultivate the power of their own souls then control their bodies, the natural elements and even other people’s souls with that power! These special beings were called — soul cultivators. Come witness how the several fragments of the dead inter-dimensional traveler’s soul and that skill book, which was not governed by the laws of this plane, were going to help Bai Yunfei become a legendary soul cultivator and craftsman!