Lone Wolf of the War of Resistance: Starting in 1942

[War of Resistance + System + Lone Wolf + Power Fantasy] A true lone wolf who never joins any organization. He's no elite soldier or assassin, just an ordinary office worker who ends up in 1942 after a factory explosion. “Where am I? Is this still China?” “Of course. Kill a Japanese soldier to activate the System.” With a curse and a rock, Li Xia gets his first kill as his welcome to the era. From then on, a god of slaughter walks the land of China. [A regular person's guide to transmigration: the first three chapters are a slow burn; the slaughter starts in chapter four.]