“ The extra-planar citadel of Ansern is named after its mage-founder. Ansern discovered the means to traverse the planar gulfs and created the citadel as a haven for his disciples in the art of planar-exploration. The disciples of Ansern continue his work and explore the countless worlds opened up to them by the work of the mage. They are cataloguing everything they discover in preparation for the greatest volume ever written: the Mondopedia, a book detailing many of the worlds. But the countlessness of the planes means that their book will never be finished.”
“ 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.”
“ A terrible teleportation incident makes inter-demihuman chimaera of all the PCs. Quoth Master Adams: 'I teleported home one night / with Ron and Sid and Meg / Ron stole Meg's heart away / and I got Sidney's leg.'”