For all people who think the Japanese dude (Ukyou) will backstab, them don't worry he will not.
He seriously love the people of that country true the reason he revolt mainly for his revenge, but he does care for the people.
Also, his Kingdom pretty much taken over by the King family because he make his daughter marry Ukyou.
He doesn't have much of a choice. His two options are to give up and work with the kingdom or try conquer them again. What he needs is supplies and foodstuff for the winter and those are things he can't magically conjure up. Since war would do nothing but further waste his nations resources and put him in confrontation with the extremely powerful otherworlders which even if he wins if he takes too long and winter hits before he can win then he's screwed. Working with the kingdom as close to possible as an equal is his best option.
Well what i can say the ukyo guy screwed up when he tried to wage the war with the kingdom after all, this actually better term than what he can ask for since he can be asked for "repparation" since he practically lose the "war"
If you don't want to be confronted with discussion of a bad manga in the comments to a bad manga, then might just not read the comments at all, or you might block the commenters who point to the ways in which the bad manga is bad. Otherwise, you're voluntarily continuing to read what you believe or pretend to believe to be bad, and then complaining that anyone would continue to read something that he or she thinks is bad.
(The business of reading bad comic books and manga, of watching bad movies, of reading bad novels, of viewing bad painting, &c, knowing in advance that they are or will almost surely be bad, has been discussed many times and sometimes at great length.)