Bright Sword: I, the Interstellar Commander, Parachute into Ping'an County

A commander in humanity's future interstellar fleet is forced to make an emergency escape after a hyperspace jump goes wrong. He brings along a damaged AI adjutant and a miniature matter-recombination device, commonly known as a “printer,” and crash-lands outside Ping'an County in 1942.

He can't directly manufacture weapons that surpass the era, but he can spend resources such as steel and rare earth elements to “print” World War II weapons modified and optimized by the AI, including Type 92 infantry guns with basic fire control, Maxim heavy machine guns with twice the rate of fire and accuracy, and “super Bazookas” capable of firing special ammunition.

Li Yunlong thinks he's a god who has descended to earth and insists they become sworn brothers. From then on, everything in northwestern Shanxi goes completely off the rails.