Regressor of the Fallen Family - Chapter 192

A back-to-basics(?) monster evolution novel.

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.

He is the ruler of the mercenary realm, an overlord that gives headaches to the leaders of any country! For the sake of his friends, he’s willing to sacrifice himself; for the sake of his family, he does not hesitate to spill blood! He is a dragon, one that soars above even the highest of heavens. He’s a power that advances triumphantly through unstable situations, stirring up both the winds and the waters.

- Description from Novelupdates

A normal guy gets hit by a truck and isekai'd. Why? Because trucks are apparently some cosmic loophole. He decides to be a dungeon, because it sounds weird and interesting to be one. Is it? Let's find out.