Nagakabouros Theories
In Shadow and Fortune, we got introduced to Illaoi, a priestess of Nagakabouros, the Bearded Lady. I am going to propose a theory on who Nagakabouros is, but first some background information. Naja is current genus name for cobras, in particular, Naja Naja is the Indian Cobra. The word Naja is derived from the Sanskrit word nāga, which means snake. Looking at the second part of the name, abouros, we see a similarity to the word Ouroboros, which is a snake eating it's own tail. It was first appeared in either Ancient Egypt or India. From this, we gather that Nagakabouros is some sort of Snake like creature. Now let's briefly look at Nagakabouros's common name, the bearded lady. There probably isn't too much to this other than appearance.
Let's now turn our eyes to Bilgewater, where Nagakabouros is worshipped. It's an island in the middle of a vast sea, which serves as a pirate hang out. As Nagakabouros seems to be a goddess of the sea, it makes sense they worship her. Something that is commonly paired with the sea in mythology is the sky, in particular, storms.
So we know that Nagakabouros is some sort of bearded snake-like deity with a connection to the sea. Seem rather familiar?
I am proposing that Nagakabouros is either Ao Shin's partner or somehow else connected to Ao Shin. The both seem to be connected to Asia, fit a similar description, and a connection to the sea/storms.
There may be further connections with Nagakabouros, such as Illaoi being a disguise.