You may like Amber RPG based on the books of the same name by R. Zelazney.
Edit after comment by Brian Ballsun-Stanton.
I have played it many a time. I like the diceless approach and the rules are simple enough to be entertaining and complex enough to add nuances. Although I find "strength" to be very weak when compared to "warfare" as states go. Same thing goes for having to buy "Pattern walk" for 50 points. It's either too expensive or should be free. That said, most of the game will revolve around politics, over the top actions, and the nature of reality. The rules work within that. If not, it is trivial to change all powers to skill with different level.
As far as the world goes, if you have read the first five books (don't bother with the rest), then you should have a good idea of what kind of games can be played. I have seen many many different versions of Amber which still had as a core what Corwyn tells us -- which are all lies or are they? After all, Brand may have been framed by Crowyn who wanted to create his own Pattern. Or maybe it's all a plot by Chaos to put a weak and feeble king to destroy Amber from within. Or maybe there are other forces (Pattern, Logrus, what else?) at work.
I have seen some heavily inspired by "Richard III" (as in the modern day version with Ian McKellen), "Shengoku" (Japan, 16th century), and even "13 warrior" (Vikings, with Grendel and all that jazz).