NewReadNovel

An alien''s accidental trip brings the protagonist back to the past, as compensation, gives the protagonist a cheat device. Low-key person, low-key development, digging holes, planting fields, mining, smelting steel, making guns, casting cannons, aircraft missiles plus submarine torpedoes, using 21st-century weapons to fight World War II. Killing people is just a hobby, annihilating Japan is just a thorough job, but before that, first tuck your tail and be low-key.