So basically, this dude's barrier is OP as fuck, as you can see that dragon (one of the strongest) couldn't even break it
that barrier can block many things AND can heal etc
as you expected, he got exiled from his country, thinking they didn't need him anymore since the barrier was up already but that barrier soon expired
King of course knew this and didn't even approve of exiling hIm (in fact, he was kept in the dark, so he was asking two culprits unaware they were at fault to look into it), while the kingdom reached doom. (King did find out and punish those two, and at that point, it was too late to ask MC to return cuz those culprits tried many methods to get him back (making him a slave etc), but none of those worked cuz of his barrier protected him)
Meanwhile, other kingdoms who heard of this and heard MC is at the xxx city, all reach out to him "Hey man can you put up a barrier for our kingdom, in return we will give you a reward"
he accepted those rewards and did 2 kingdoms, and one of them offered the land, just barely functioning, but he accepted it anyway and with his barrier protected his land, etc, and res demon all that.
basically, to the end of the latest chapter that is on NovelUpdate, his barrier is OP af, can reflect magic and physical, can heal someone
He is so confident that he can win with just a barrier and he isn't wrong on that.