How a Realist Hero Rebuilt the Kingdom: Omnibus Vol. 2 (manga)

Contains the full Volume 3 and 4!
The Subjugation War Begins!

With supplies in place, plans made, and alliances forged, Souma's mission to subdue the rebelling nobility has begun. With a pocket full of tricks, loyal subjects, and modern knowledge, this should be easy! Well... not if you want your civilians to escape unharmed. Or if adventurers keep treading across the battlefield. Or if your nosy neighbors think this might be the best time to launch an invasion of their own. As the conflict expands, it's up to the crew to find a way to win without falling prey to tricks, manipulations, and schemes behind the scenes. Can Souma survive? And with his reputation intact?