“ Someone needs the blood of a dragon, given willingly, to make a rare potion. Guess who gets hired to sweet-talk a dragon into giving up some highly powerful blood?”
“ A golden skull contains the spirit of a person who has been magically entrapped in an ethereal undead status by an ancient ritual. The person was boiled alive in a golden mixture until nothing remained of him except the bones, now covered by a golden layer. Whoever has these golden bones, controls the spirit and can command it. It can assault the living with wind and storm. Manipulate objects and communicate with the living. (Inspired by Anne Rice, Servant of the Bones)”
“ 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.”