I thought demons were agents of chaos who utilized logic and reason in a rational manner only a demon could understand, but demons and other power hungry individuals have been around for a long time, so shouldn’t their be some god slaying artifact lying around waiting to be used to empower somebody with the power of their chosen sacrificial god? God’s are powerful, so powerful in fact that they have few true threats, so when faced with a genuine threat many might simply fold. I know many in power dislike the prospect of losing it and will try to avoid it. Their are weapons designed to harm demons so the reverse should be feasible as well. It’s what I would have done if I was a powerful demon. Kind of the penultimate manner in which one could flip off the divine. Most fantasy settings have one lying around somewhere in a forgotten and secure location as the gods dislike having mortals know they have a weakness as we tend to find and then try to exploit said weakness once known.