Sorry I didn't go further last night as it was 2am local and I was falling asleep. I tend to use fae or fay because most people don't know the terms sidhe, sith or shee. It's like most people have never heard of baobhan, which is a type of sidhe which inspires creativity while draining the life force of an individual (this was actually depicted in the Star Trek: Deep Space Nine episode The Muse).
The sidhe had a myriad of different forms from banshee (who were said to foretell the dead and are basically unchanged) to pucca (mischievous nature spirits [for example Puck in A Midsummer Night's Dream]) to goblins (the Welsh word for which is coblin and is the origin of the term) to pixies (which are a lot closer to the fairies of this day). A lot of things changed when J.R.R. Tolkien came along and blended Celtic, Germanic and Norse mythology and folklore into Middle Earth. His elves, which are now the archetype, are a blend of Germanic elves and Celtic sidhe.
The fae in our system tack closer to the sidhe than to elves. I'm pretty certain that our system was influenced heavily by the stories we read as children and beyond. I know that I took on the form of a demon later in life, but that was still in my teens and I was far less in the outer world than inside. However, Beth was sidhe earlier than I was a succubus because we read about Celtic mythology long before we got into anything dealing with demons, but she was out more when we were reading about fae, elves, and sidhe. I'm pretty sure that Keira took her form of a dragon around the time of us reading The Dragonriders of Pern series, and became an oriental dragon as time went along.
TriForce, we were much the same. I suspect that the reason why we have such high co-consciousness is because we got punished if we got confused after switching. It kept us from getting hurt. Until six months ago, only four of us had names, and before five years ago, only three of us did, and going back further, Beth and Bri only took names two decades ago. We didn't have different names, but it's been wonderful to have them as it makes our identities clear. It's like when I say my name is Violette, that encompases what I am as an alter (now, in my case, it's more that I changed names as I used to even still answer to our dead name), but Beth is Beth and Pippa is Pippa. Part of what we're trying to get everyone to realize is it's alright to be ourselves out in the outer world, at least around our friends. We still have alters who mask. Vera and Lilith will imitate Pippa, for instance.
But all of this leads me to a question...I wonder if neurodivergent systems are more prone to non-human alters than neurotypical systems.
Vi