I'm Just a Lie-Flat Live-In Son-in-Law, So How Did I End Up Conquering the Northern Tribes?

After transmigrating to a fictional world, he becomes a lowly live-in son-in-law. The little son-in-law decides to lie flat. He’s tired of trying and wants nothing more than to fish, watch the show, and visit the pleasure houses. But he can’t abandon his wife, ignore his father-in-law, or turn a blind eye to the imperial court... So the little son-in-law gets down to business, making waves in the world of commerce, weathering the ups and downs of court politics, and earning the title of Wolf Dwelling at Mount Xu... Just like that, he transforms into his wife’s dashing husband, his father-in-law’s ideal son-in-law, the female emperor’s favored minister with the Nine Bestowments, and a certain prince’s adopted... father?