Acheswan but they're a witch and a demon
Okay but please PLEASE consider
An #AcheswanFantasyAU where Black Swan is a witch belonging to the Garden of Recollection Coven and Acheron is a demon who is also her familiar AND A SHAPESHIFTER but she can only turn into one thing - a tiny snake with vibrant purple scales and red dots behind her head (she's a cutie).
Several fun fact about this AU because it's been haunting my mind for YEARS now:
All witches are humans who are able to perform magic. The type of magic they specialize in depends partially on their coven (same as fraction in the canon universe) and the aeon they serve. Example: Swan serves Fuli and she specializes in magic that deals with people's minds, including their dreams, memories and even their overall health. Aventurine serves Qlipoth and thus specializes in shielding spells.
Acheron is an oni, which is an entirely different species than humans. They cannot perform magic, but the enormous amount of magic energy circulating in their bodies allows for some extraordinary abilities, such as being able to shapeshift. An oni can only shapeshift into a specific animal. For Acheron it is a snake, specifically a grass snake. This is a talent each oni is born with, it awakens in early childhood and is considered absoulutely normal in their culture.
I headcanon both their appearances to be very different from canon. Black Swan most often wears a brimmed hat, a long elegant lavender dress or a long skirt with black corset. She has A LOT of moles and freckles all over her face and shoulders. She is also kinda short, especially next to Acheron.
Acheron has traits typical for an oni in this AU, which are really f*cking scary to a regular human or even a witch: eyes that shine in the dark, long fangs (and also molars much bigger than those of humans, similar to those of predatory mammals) - which allow for a SIGNIFICANT bite force (translation: she can and will crush bones), pale skin (also gets sunburnt easily) and - most importantly - long red-colored horns on her head with one being slightly shorter than the other (consequence of a childhood trauma). As an oni she posesses a powerful roar (reference for that being a tiger roar), but she is also able to purr much like a house cat. She tends to wear dark baggy clothes consisting of 3+ layers and she patches them up regularly. She has several old scars. Most prominent ones are on her thigh and her shoulder, both of which she covers with bandages.
Black Swan is a mysterious forest witch. Most of the time she is occupied with studying magic, helping out the people of villages surrounding her forest and doing the work deligated to her by the coven's higher-ups. She also regularly fights off the attacks of witch hunters with the help of her magic. Though the hunters have been gaining numbers and recently it's been harder and harder to keep herself safe.
Acheron has been wandering the human world ever since her home (Izumo) has been destroyed in a terrifying Apocalypse-level catastrophe caused by an unknown aeon. She never really managed to find her place in this world, where she is seen as a monster. Though she knows she is likely to be treated unfriendly, she still tries to be well-meaning towards humans, which even secured her a place as a guardian of a small farming town for a short while in her past.
As per the time of Acheron and Black Swan meeting each other, all oni are considered to be extinct with little to no knowledge about their civilization. Witches studying demonology describe them as 'demons', though 'demons' are a paraphyletic group of many unrealted magical species. Acheron has been living among humans for long enough to be at peace with this term even though it is considered derogatory by many ordinary humans (non-witches).
Black Swan saved Acheron (in her snake form) from a snake-trap, not knowing that she actually brought home a 'dangerous and unpredictable wild beast' (as demons are described in some witch literature). Not only that, she also treated her wounds and learned to handle her, with snake!Acheron even reacting well to being picked up (my poor baby might be touch starved after all). Acheron later reveals her true nature and is genuinely surprized to be met with interest and care rather than disgust that she experinced from most humans. Thus, the nickname 'the kind witch' stuck.
I'm SO SO SO EXCITED to share more of this AU if anyone is interested in it. This AU is my passion project and my hyperfixation. I swear I love these girls so much OMG!!!!!!
