You know what’s interesting (to me anyway)? Is that if you derive the meaning of creatures or supernatural entities from their etymology, as I like to, it presents a fun and intriguing contrast between demons and angels.
Demons would be divine, guiding spirits or lesser gods, possibly with some connection to division. Angels, on the other hand, would be messengers or swift couriers.
Just a little etymological quirk that amuses. And probably plays some part in how I conceptualize demons. (I do the same thing with fairies; I associate them with fate or speaking fate.)
Gotta love how they both have some Greek roots.