The Strongest Single-Soldier Enemy-Killing System in the War of Resistance

I want to read a book similar to "The Strongest Single-Soldier Killing System of the War of Resistance". Travel through the parallel world during the Anti-Japanese War, and carry a single-soldier killing system! He can sneak attack and never attack head-on. Never beep if you can do it, Barrett's headshot, anti-aircraft machine gun's flat shot, Vulcan cannon's sweep, all