Forgotten Title Forgot the novel's title (a very entertaining and funny novel)

So I don't remember much of the novel but I do remember that is has an OP female protagonist. She has a very unique personality because it changes depending on the weather. On sunny days she is normally very cheerful, carefree and always positive whatever the situation she was in. On rainy days however she turns to this very gloomy character, like the world is about to end. As for the plot it's basically just about two kingdoms fighting, the story just revolves around the war

 

I just got interested in the novel only by reading your summary

 

Yeah it's a really interesting story, it's a combination of comedic and has a bit of dark elements here and there