MTL - Man Huang Feng Bao - Chapter 443 latency

In the middle of a deserted island, a small boy wakes up with two sets of memories: one from his few years of life and the other from a man who lived to adulthood and achieved great things. When he least expected it, a powerful master appeared on the island and took him in as a disciple, revealing a shocking fact: magic exists in that world, and, thanks to it, humanity managed to conquer the galaxy.

One day, the stuntman found that acquaintances and unfamiliar people were looking for him through various channels. Even someone from a certain department of the country came—

An ordinary student accidentally traveled into an other universe and became the king of a small kingdom. He had gotten a “Cheating Code” of life and was able to complete something extraordinary. This is the story about a king that was able to conquer continents and leave behind him an ultimate legend that will be recited between every generation to come.

- Description from novelupdates

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.