Protagonist: Lin Yan (a modern social animal, knowledgeable about basic agriculture/management/history, pragmatic and a bit timid, later forced to become a "dirty politician")
Era: The fictional "Era of Great Controversy" (similar to a mixture of the end of the Warring States Period + the end of Qin Dynasty + the end of the Sui Dynasty, the world fell apart, and seven or eight "kings" fought in a melee, which just happened to "compress time and space" such as Ying Zheng, Liu Bang, Li Shimin and other big bosses into the same chess game, each with their core team to separate themselves)
Goldfinger: It's not a system, it's "the General History of China + common sense of modern social sciences installed in the brain" (for example, knowing that "land annexation is the root of troubled times", "logistics determines the outcome of a war", "information transmission efficiency > troop strength")
