A demon comes to exist when a being within a system perceives itself to be powerless relative to what it needs and what it wants. And when it perceives the other elements of that system that it is a part of, to be against its needs and wants (and therefore its best interests). And so, instead of loved, it feels harmed. Instead of unified, it feels disconnected. And it decides to separate itself further by pushing away and becoming oppositional to what it perceives to be its adversary, only this time that adversary is the system of the universe at large and the other beings within that system. From there, unencumbered by the rule of not harming others, it begins to get its needs met in whatever way is most effective. And that way is usually harmful in some way to others.