Board Thread:Warhammer 40k General Discussion/@comment-14745711-20130825021657/@comment-3580035-20130826070505

All the Chaos Gods are oversized Daemons. Daemons are formed when enough of a specific emotion is present to form a new type of Daemon (like in the case of Slaneesh), or if a Daemon expends a portion of its energy/being to create a new sub-Daemon. So it all really depends on what you label as a god-level demon.