Demons are a kind of Changeling.
They have some similarities. They draw energy from human belief, they are mystical beings inside human bodies, they can with some effort evoke their true forms (apocalyptical forms/wyrd), sometimes they can live inside objects (earthbound and inanimaes). Like the fae from Dark Ages: Fae, they say they created the world, they gave the humans power upon the world, and they can make pacts (oaths) with mortals to get more power. Demons are in fact more powerful than changelings, but this may happen because much more people belive in demons than in fairies. And perhaps we can find just demons, but not angels, because the Endless Winter is too close. Just nightmarish faes can take form in this age.- It's definitely possible. Considering how one story about the War in Heaven is that there were three factions of the Angelic Host. One third remained with god, one third rebelled with Lucifer, and the last third decided to remain neutral in the war. This neutral side was approached by God and thrown out of Heaven altogether, but they weren't sent to Hell with the Demons. They were to wander the earth, shut out from Heaven but not cast into hell. These Angels are said to have become the Fair Folk... which befits the above question.
