Well I would say there's at least some success here, isn't there? Despite all the despair, it looked like Peromei was at least placated to some degree. She didn't try attacking the city at least and is apparently leaving Junko to us to deal with.

[Just. With that nice little warning that if it happens again she'll be back and won't hesitate in "dealing" with the problem again.]

So there's some hope there. [He is never going to look at that word the same again.] I mean, no matter how determined that girl is, it's only one as far as we know of. Even if there are others, there's still a greater number of people who would want to counteract it.