Su Mu time-travels and becomes a hundred-year-old man. In an era of turmoil, his wife and son are entirely slaughtered by the Northern Di, leaving only him and his twelve-year-old granddaughter to depend on each other. The authorities forcefully conscript his granddaughter into military service, so Su Mu, already at a hundred years of age, resolutely decides to enlist in the army in her place, awakening the Hundred-Year-Old God of War System. Relying on the system, the old patriarch gains divine strength and blade techniques, running amok and slaughtering his way through the battlefield!