I know, I know, this isn't a DC story, but if you liked watching Avatar: The Last Airbender, loved Zuko, but wished it was a bit more 'real'? THIS is a wonderful WIP story that is amazingly well written and up your ally:
Embers by Vathara on FF.Net
Currently 47 chapters long, it'll take you at least a week of reading/schooling/working to get through it all, and like I said its not done yet (and won't be for a long while yet, I hope). And while the story focuses mainly on Zuko, it seems more to me a retelling of the Avatar world as it should of been if the writers had bothered to focus it towards adults instead of children. For example: the four separate nations are *actually* four separate nations with their own traditions and cultures that clash and cause misunderstandings between them.
The author updates every 3 weeks on a Thursday-night/Friday-morning. The story starts early Book 2, and while the story progresses, you are introduced to 3-dimensional original characters and the original characters shine with all of their character strengths AND weaknesses. And while side-plots, conspiracies, and 'new' ancient history is revealed each chapter, everything is a slow, wonderful build-up that enhances the depth of the main plot.
The story will delight you BECAUSE it is heavily entrenched in contrasting the differences of the cultures, and heavily explores the REASON there is an Avatar - to be the bridge between the human and spirit world.
That is all. XD