Alliance of the two kingdoms

Last heir/heiress of your declining bloodline, you've been at war with the neighbouring kingdom for centuries because of the feud between your founding gods. As the losses of the war accumulate with no end in sight, the princess of the neighbouring kingdom offers for you to put a term to this endless conflict through wedding with her sibling, the Crown Prince/Princess. This story is heavily customizable, and I've yet to find how to put the questions in the right order, so, good luck with that ! Any suggestion on how I could improve it are welcome. Small inspiration from SubZero by JunePurr on Naver Webtoon, go check it out if you like this kind of stories !