[System notification: Host, you have arrived at the front lines of the war between humans and demons. System reward: Demon-Slaying Saber Technique]
Chen Feng, a recruit, stares blankly at the Type 95 assault rifle in his hands.
A system with way too much fighting spirit insists that the military camp is a Demon-Suppression Bureau, the instructors are "century-old demon generals," and drills are "monster sieges." It even issues him missions to slay demons every day.
All Chen Feng can do is use the [Demon-Slaying Saber Technique] in hand-to-hand combat, the [Indestructible Diamond Body] for weighted cross-country runs, and the [Truth-Piercing Eyes] to line up his shots...
He becomes unbeatable in combat, hits a perfect score in shooting, breaks the cross-country record, and rises to become the strongest soldier in the entire military.
On a mission, facing a vicious drug lord (a "millennium-old great demon" in the System's eyes), Chen Feng slides in with a flying tackle and shouts, "Demon, where do you think you're running?"
When he is decked out in countless medals, the System is moved to tears: [Congratulations, Host! You have swept the demon lairs clean, and there are no more monsters left in the world. Your merits are complete. You may retire!]
Good water writing...