Doomsday Secret Realm: Only I Understand History to Save China

The global secret realm merged with the blue star, natural disasters occurred frequently, and the territory was reduced sharply. China missed the opportunity of the secret realm due to historical faults, and its national power plummeted. Only the time traveler Duan Chen knows the complete history, travels through the secret realm of the mythical Three Kingdoms, and uses history as a blade to prop up the mountains and rivers of Jiuzhou that are on the verge of collapse.