I do prefer too ! Manichean or monotheistic way of thinking about démon is really interesting on Fantasy i think. It lacks originality.
But i disagree about the Idea of just a semantic question.
I'm not trying to define the Word demon in an absolute way.
To me it is a technic question, regarding the setting for the rules are made to serve thé setting.
Then thé thing i'm looking for is the link between both for it defines technically what pc Can Do or not.
That's not a semantic question here, but truly something that Comes from both the définition given by the setting, and those given by the rules, that don't match each other.
But as pc Can bind démons or banish them, it's important to know what is actually a démon in the setting.
Brior gave me the answer i was looking for : a demon is a creature from another plan, whatever it is.
Then bloodlings, abyss Worms, and insectoids, for example, are démons, since they Come from outer plan.
Then they Can be bound or banished.
It's far more interesting than just chumog créature only. ^^
Then Brior you answered my question pretty well ^^ thank you!