Assassin's Name

The books are also titled: "Step by Step to Camp" and "The Cultivation of the Calculating Demon" Being green, I drove fast and was knocked off a cliff. When I woke up again, I came to an ancient Yin Kingdom. He has the body of the best assassin in the world, but he doesn't have his master-level martial arts skills. I wanted to live a carefree life, but because of this assassin's body and name, I had to change constantly in order to survive. Let's see how an assassin with advanced thinking and knowledge of modern people can "fight monsters", upgrade, and pick up girls in this era of rampant martial arts...