Pillars of Eternity has a lot going on within it. I find it incredible that they got as much interconnected lore working given the time they had. Me thinks Josh and others had been day dreaming some of these things for a long time!
For me I love that it's set in a "New Word." Age of Sail and Colonization and all that. Where old established cultures are confronting complete unknowns, in every imaginable form. Isolation on the frontier, colonial conflicts, lack of or imperfect law of land. Especially since it's exploring this era of history from a fantasy perspective. For me it's just a very fresh setting to experience and I feel I've only just gotten a small taste of it.
I also love the idea of man made Gods. The whole setup of them actually being powerful, but also having seemingly abandoned most of kith-kind creates a really interesting dynamic. This contrast between a desire to be free, but also subjugated under a super-ordinate being. And how existing faiths will be shaken. Who knows maybe there are even true gods, or maybe Pillars metaphysics is far more secular. Animancy is sort of presented as a secular pursuit within the world, but is viewed through the eyes of jealousy and superstition by those that ascribe the views of old. Either way it's an incredibly different way to setup the metaphysics of a fantasy world.
So how about you?