The Demon's Soul - Chapter 43 Background story- Part 1

Amid the silence of the aftermath, a sealed envelope was found resting beside the fallen Infinity Blade. Its edges were worn, as though it had been carried for many years, yet the seal remained intact. Gok, known for his stoicism and strength, had written it long before the final battle, anticipating that one day his journey would reach its end.

Li Xu occasionally got a sign-in system, and his life has been different from now on. Enjoy life, look at the scenery, sign in, spring flowers bloom, and face the sea.

- Description from novelbuddy

Yun Woo is the youngest author in history to enter the literature world. His debut work was a massive hit but this success was short lived for the unprepared.

A lecherous army special task force soldier from 21st-century Hong Kong is selected to travel back in time, choosing to go to the Chinese Warring States Period. Unfortunately, the time machine runs into an error during the experiment. With no foreseeable way to return to the present, he must use his combat skills and knowledge of history to thrive in his new life in the year 251 BC.