The General Who Came from the Siheyuan

This novel is set in a courtyard compound and centers on the Korean War. There will be plenty of punishing the beasts, and there will be a System, but it won't be overpowered. The protagonist has no saintly tendencies: he's decisive and ruthless, won't bow to the courtyard elders, and shows no mercy. He repays kindness with kindness and settles every grudge.