The idea I had for the nation my character idea was from took a lot of inspiration from world war 1 and 2 eras of nations like persia, japan and ofcourse the republic of china. With them having been pretty peaceful before the futile war kicked off, going through some internal strife as one of the few nations that wasn't swole enough to really stalemate the european invaders until they realized this massive stone deposit that they'd used for more peaceful things like purifying their lakes and defending against harsh weather could be used to basically glass massive areas. The realization was to be their idea of the nuke and the fear of it grew into an appreciation of raw power basically. The initial idea was that the character was gonna be adjusted to handle the stone better(i guessss it's still on the table with the egotism) and serve as a showcase for their power in combat, for the sake of restoring their clan's name. Like it'd be the country basically saying. 'We can make more, hire us to slay your enemies and we can be rich with an endless wartime economy' kinda deal. Kinda like some msg type beat. 

Also [@ERode], I did more research and got an even better idea that more simplistic scientifically. The stone magnifies sound that gets trapped in it with light. Basically I had no idea until now, but the more hertz sound has, the higher its decibels will be. Decibels is intensity and hertz is frequency(like how many waves are in that space), and when the decibels get past like 7000, they start vibrating enough to burn things. I was thinking of decibels when I had the idea for the polymathy through the stone. The stone would basically only be able to help someone trap and control dangerously loud sounds as it is now, so I'll probably scrap the sound idea since it was specific to the character's branch of the country's royal family, and not the country's weaponry as a whole. It would take an incredibly massive crystal(bigger than I'd initially assumed, like the top being the tip of a small mountain, while the shaft extends into the ground, past the base sized) for them to glass anything. And I think that's a cool idea, but beyond that, I'll be back to the drawing board on the individual character's polymathy.