From the Start, I Marry Into the Family and Build a Barrett by Hand to Conquer the World

[Strong male lead and overlord + passionate action + no harem + revenge and conquest + no System + farming and infrastructure + firearms] A former special agent transmigrates and wakes up as a live-in son-in-law? No need to panic! Watch him defy fate and change his life with modern knowledge! By chance, he rescues an imperial envoy traveling incognito who has been hunted by villains. On the journey escorting him back to the capital, he shares life and death with the Eighth Prince, and the two become sworn friends. In this ancient world, outwardly prosperous but rotten beneath the surface, he uses modern wisdom to bring steelmaking and honeycomb coal to the people, improve stoves, revolutionize heating, and solve everyday problems. One novel dish after another is served at the table. The fiery spice of hot pot and the delicious aroma of stir-fried food instantly win everyone over, earning lavish praise from nobles and officials, who call it “the finest food under heaven.” At court, powerful clans scheme against one another, form factions, and seek to manipulate the government. He slams his hand on the table and declares, “The great clans? They’re no more than barnyard fowl and clay dogs. If they dare stand in my way, I’ll blow them to pieces!” His words are pure swagger. The emperor is incompetent and treats the people like grass. He points his sword at the court and proclaims, “If Your Majesty is unjust, I’ll take your place and bring peace to the realm!” With the war going badly and Jiaozhi and Goryeo invading, he dons his armor and leads his troops into battle. Using modern military strategy, he routs the enemy, reclaims lost territory, brings three kingdoms into his empire, and builds a mighty Huaxia that commands respect in every direction. The Japanese pirates of Dongying refuse to give up their wicked ambitions, so he personally leads five hundred thousand elite troops across the waves and strikes at their heartland, wiping out their country for good and making sure they never again covet an inch of Huaxia’s land. See how Xu Zilin, a live-in son-in-law in another world, unifies the realm, writes his own legend, and lives a thrilling life worthy of one.