“ This really comes from an ancient Chinese novel. Imagine during the PCs' travels, they come to a place where the gender roles are completely reversed. What adventures will the PCs encounter in such a place?”
“ In cultures and langauges with very few acceptable personal and family names, nicknames will be used. These nicknames will be based on their physical traits and personalities. So instead of five Ryon Khans, you have Big Ryon, Little Ryon, Fast Ryon, Ryon the Priest, and Ryon with coin. It will make finding people, for an outsider, difficult.”
“ When you sleep, your soul briefly returns to the place where it was created/goes to when it dies, and seeks nourishment. Everybody's soul is created with a little link (or you could say a greater entity calls it back) to that place so that it can return easily, but upon death, the soul returns via that and annihilates the link as if returns.
Also, as an added thingy, you could say the entity supplying the link, or residue of the links themselves, (whichever) is the source of all arcane power.”