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?
A sentiment weapon that is very impressionable in terms of what is right and wrong, akin to a child. Currently, being ownerless, it is not very powerful. However, once it has found an owner, it can provide significant boosts to the wielder in an area or areas the wielder most desire. What adventures will this sentiment weapon go through? How will it develop itself in terms of power and personality?
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.