Divine Rivals

It's a youthful wartime romance wrapped in magic.

My only issue with it (and the reason I initially wasn't going to finish) is the letter writing is used to tell large chunks of the world's history. The history itself is fine and important to the plot, it just felt lazy to have one character write it out to another character.

I'd still recommend it though. The writing is beautiful and the end will make you wish you had the next book in your hands already.