Tremble, Conquerors of the World

In this war-torn continent, countless outstanding people have arisen due to the situation, and I, a modern person in the 21st century, came to this world with the memories of my previous life and the skills passed down to me by my grandfather. As a lover of military history, I shouted: I come, I see, I conquer! When I finally came home for vacation that summer, my father sent me to my grandfather's house in the countryside. My mysterious grandfather took out an old yellow book from his ancestral house and said to me: Grandson, actually, my grandfather has a secret that he has not told his family for so many years. I feel powerless recently, and I am afraid of leaving regrets. Today, while you are here, I will explain to you, in which era was my grandfather poor? People often starve to death, but I was lucky enough to meet my master who taught me this. As he spoke, my grandfather handed over the old yellow book. I stretched out my hands and took it. Grandpa continued: I have no education. I only learned the ability to treat illnesses and save people. With this ability, I built a house and married your grandma, an educated college student. I originally wanted to teach it to your dad, but your dad doesn't believe in these things. Today, while you are here, grandpa wants to ask you, are you willing to learn it? Just after that day... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.