How a Realist Hero Rebuilt the Kingdom (Manga): Omnibus 4

Souma has now proven his military might in the successful siege of Van, but the Amidonian foothold he's secured continues to be a hotbed of contention. Disgruntled Prince Julius calls upon the Gran Chaos Empire in an attempt to tip the scales during the ensuing peace talks. Souma thus finds himself meeting directly with Jeanne, sister to the empress, and the negotiations take an unexpected turn. Elfrieden isn't out of the woods yet, however. With the fates of Georg Carmine and Castor Vargas in his hands, Souma has more tough decisions to make...