An extremely shiny piece of bling, so big and amazing that it inspires anyone who sees it to ask questions about its origins, the bearer, and most anything else they can think of.
A classical enchanted weapon…
All spell casters gain their abilities through a form of demon possession. So in order to gain magical abilites, PCs must track down and trap demons. Of course there are some pretty powerful demons, if the demon is stronger than the PC, the PC could find themselves subjugated to the Demon's will.