Consider the idea of spontaneous genesis of life, as used to be belived. What strange kinds of life might arise from modern substances? What kind of vermin would a landfill produce, or an oil spill on the ocean?
A demon who isn't some hideous creature bent on consuming souls, bu is, in fact, a likable chap who enjoys having pleasant chats with people - trying to talk them into becoming his servants.
Ten powerful magic rings created by an Archmage have scattered to ten random people (suggest only one is PC). This happened when he died in battle. Whoever gets all ten rings inherites all the power the Archmage invested to them over his 200 year life.