I'm sorry, I feel like we missed something important. We were theorizing about what might be causing the problem, and then suddenly we're in some presumably hidden location looking at a gigantic fuckoff magic crystal that's worth more than the entire continent? I feel like there wasn't really enough explanation for this.
Also, sudden downpours in regions plagued by drought are a natural disaster. That's how you get flash floods and landslides. This isn't a good thing, realistically, but I get the feeling that will be overlooked for the sake of the story.