I Fell Asleep While Standing Guard and Woke up Wearing a General's Coat.

Lin Mo traveled through a parallel world and became an airborne soldier, but accidentally fell asleep while standing guard. When he woke up, he found an old man in military uniform looking at him kindly, and wearing a coat without a military rank uniform. Lin Mo was just about to say something to ease his awkward mood, but when he looked back, the gun was gone!