Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 421

Throughout this current life of mine, I will pay no attention to my past lives, nor will I seek future lives. I wish to live vigorously, to pay back debt of gratitude and fulfill duty to avenge, to defeat valiant heroes from all species, and to proudly laugh at all the Gods and Demons of the Six Path of Reincarnation!

- Description from Novelupdates

This is a story about a young man who sought to fight against his destiny. With the help from billions of Dragon Energies trapped on the Rising Dragon Pillar in his body, he emerged from the dark and quenched himself with the blood of ancient dragons. He fought the heaven with the Buddhist Art for the people he loved and built the Eternity Kingdom with his own hands. This is a story about the rise of the Martial Emperor who will rule both earth and heaven.

- Description from Novelupdates

Kira was living the life that others could only dream about. He was gorgeous, rich and very popular - the kind of guy that drew students from all over the place just so they could brag to others that they went to the same school as him. He was undoubtedly the number one heartthrob that every girl dreamed about.

[You have transmigrated, named Gu Sheng, and are a farm boy.][This is a dynasty in chaos, where demons and monsters lurk and bandits run rampant; as someone at the bottom, you face hellish survival difficulties.][You decide to lay low.][You awaken a mastery panel.][You breathe a sigh of relief, you can start grinding.][You grind Chopping Wood to Perfect, chopping bones and breaking tendons with ease.][You grind archery to Perfect, becoming a godlike archer who can hit a louse at a hundred paces.][You learn the Iron Stone Fist, set foot on the path of a Martial Artist, and grind it to Perfect, with punches as heavy as a million pounds.]……[You learn the Longevity Eternal Youth True Art, greatly extending your lifespan, giving you more time to grind, and greater hope to lay low.]……[You grind to the limit, steadily laying low, and one day you suddenly realize, you are invincible.]