Right! I’m back from a week of school visits, leeches, ridiculously steep trails, dalbhat tarkari twice a day, and scribbling notes on gender in a made-up world. So where were we?
I may be *slightly* taking the long way round to answering these questions....
So let’s start by talking about gender in the Empire of Halassur (which of course is neither Jev’s nor Laj-jas’s home context, but bear with me). Halassurq society is the most gender-stratified in the gameworld. Its binary classifications of human nature include the following:
Feminine: agriculture, medicine, priesthood, philosophy, astrology, book-writing, home, garden, stars and moon, night, water, tides, designing things, intellectual labor, theoretical Theurgy, alchemy, giving birth, green, blue, black, robes, veils, long braids.
Masculine: hunting, war, government, trade, market, oral tradition, epistle-writing, travel, sun, day, fire, constructing things, physical labor, practical Theurgy (notably the military sort), siring children, red, yellow, white, tunic and trousers, makeup, short hair and lengthy beards.
These gender norms (and the pro-natalism that pervades Halassurq culture) are strongly reinforced by the Empire’s religion, which reveres Great Mother Ummay, her Consort Kormuz, and Evren the Firstborn. The heart of divine reality is a gendered family unit; the Halassurqs think the Karagonds’ genderless “Xthonos” is a laughable corruption of Kormuz.
That said, as with any real-world binary gender norms, Halassur’s aren’t followed to the letter even by broadly socially conforming cis people. Agricultural Theurgy is largely done by women, despite crop-growing being rather practical Theurgy. There are male intellectuals, though they’re treated as exceptional and not very respectable.
And the Halassurq language (which is older and simpler than the rest of its civilisation) doesn’t have grammatical gender at all. It uses the gender-neutral “o/onu” rather than “he/him” or “she/her.” (A feature shared by the Nyryq dialect spoken in the Hegemony.)
Now we come to Nyrish culture, which has been shaped in reaction to the strong gender binaries of their cousins in Halassur. The differences stem from two main sources.
First and more flamboyantly, in the century before the Karagond conquest, there was a popular sect in the Nyrnakan Republic who abandoned the Nyrish gods to worship the dominant Halassurq triad–but with the twist that Evren the Firstborn was reinterpreted as an androgyne. (The Halassurq holy texts don’t specify Evren’s gender, as o was sacrificed and resurrected in the form of a dragon before o could fulfil any of o’s gender roles.)
This widespread Heresy of the Firstborn popularised the idea of a sacred third gender–people who performed both male and female roles and dressed in a striking mix of masculine and feminine styles/colours. Most of the Evrenite priests were from this third gender, as over time were a number of prominent Evrenite intellectuals, soldiers, and artists. The outrage of the faraway Halassurqs did nothing to reduce the popularity of this reinterpretation.
Like all Nyrish religion, the Evrenites lost most of their credibility when their gods failed to hold back the Karagonds. So the literal sacralisation of androgynes didn’t last; but the concept of a third gender remained, and androgynes remain highly respected in Nyrish society.
Second, a more mainstream current in Nyrish society prioritised the needs of family and tribe over Halassurq gender rules. In isolated pastoral tribes, a person might well be called on to carry on a family member’s expertise regardless of their designated birth sex. The doctor’s son was often more likely to make a good doctor than the huntmaster’s daughter, and vice versa.
Because of the strength of gender norms in the Halassurq root culture, the Nyr didn’t simply shrug off their sense that this was problematic. But they evolved a ritual that helped justify it: at age 15 a child would be formally named after their most recently deceased relative, regardless of gender, and seek to take on that relative’s most vital roles within their community. This spread widely until it became the near-universal norm.
To be clear, a Nyr named after their recently deceased grandfather will not be socially considered male – there will just be an expectation that they’ll try in some significant way to fill the gap in the community left by their grandfather. That goes beyond merely the gendered roles. Maybe grandpa was one of the great hunters, or one of the great tailors, or one of the great talkers and tellers of jokes. Maybe he was known for his affection to the village’s children, or his conflict resolution, or his ability to hold his liquor.
Of course, it will likely be impossible for our young Nyr to take on all of those roles; there’s a recognition that not everyone is well-suited to take on a family role (and a rich vein of comic stories and jokes about e.g. people who try to take on their uncle’s role as a talker despite being desperately shy). But as long as they’ve taken on some, they’ll have met their filial duty.
So the Nyr still more or less inherit Halassurq ideas of which objects/roles are masculine or feminine, but there’s no surprise (let alone shame) when an individual performs roles of a different gender. Rather, there’s an assumption that they’re playing an important role for their family/community by doing so.
Between the cultural prevalence of androgynes and the naming convention, there’s also no way to know someone’s gender from their name or role; if they don’t clearly present as male, female, or androgyne, there’s no way to know besides asking them. But (due in large part to the legacy of Halassurq attitudes, where asking someone their gender would be a deathly insult) the Nyr consider it impolite/embarrassing to ask, and so generally make highly subtle indirect inquiries or just let it go unresolved. All in all, it’s a reasonably comfortable culture in which to be nonbinary.
Which brings us to Jevahir, the Nyrish nb person who will be popping up soon in Game 2–named for their grandfather, and inheritor of his roles as hunter and external diplomat. My current conception of o’s gender (to use the Nyrish pronoun, though singular-they will be an acceptable Shayardene translation) is that Jev is “unknown gender,” even to onu-self. No point in the Nyrish trinary feels right, so o doesn’t see a need or reason to claim any of them. O has become adept at fending off the periodic attempts of other Nyr to ascertain what sex/ gender o is.
Jev wears hunting leathers, which are associated with a masculine role, as is the kohl o likes to wear around o’s eyes, but o wears o’s hair in a feminine braid. That isn’t the sort of strikingly androgynous presentation that would lead other Nyr to class o as third-gender, or indeed to assume much of anything.
Let’s turn now to the Abhumans–or the Seracca, as they call themselves. Without getting sucked too deep into that lore-pot: the Seracca see themselves first and foremost as spirits, which are immaterial, infinitely changeable, and have no fixed nature. (This is a contrast with the northern human creeds, all of which believe in a material soul rather than an immaterial spirit.)
From ancient times, the Seracca have revered animals, seeing them as spirits that pursued different courses through the world and discovered new glories. Through self-change (i.e. auto-Plektosis), the Seracca seek to reclaim some of those animal perfections, while retaining the human glories of intellect and conscious self-change.
The Seracca are convinced that Spirit has no gender. All the dimorphisms, binaries, trinaries, and other categories are one more changeable aspect that comes with flesh. To understand the sexual dimorphisms of the body well enough to change them is praiseworthy; many Seracca will seek to change sex at some point in their (long) lifetime.
To change one’s body to be intersex or no-gender/no-sex is semi-sacred, as one then more closely reflects the nature of Spirit. Abhumans from the guild (Yega’a) of Seers, the religious/ritual specialists, are particularly likely to make this change–some after they’ve had children, others before.
Which brings us to Laj-jas, the impish, lithe, and whiskery member of the Merchant Yega’a whom you’ll meet in the Merchant’s Pale of Shayard. Laj considers themself to be gender-variable, with their spirit shifting frequently between genders faster than their flesh could possibly keep up. They therefore dress and present accordingly, based on how they feel on a given day.
Laj changes their physical sex much more often than the average Seracca; generally by the time one transition is finished, they’re ready to take pride in the accomplishment for a few weeks, and then start shifting their body in a different direction. By contrast, they feel they’ve honed both nose and tail to perfection; those remain the same whatever other changes Laj may initiate.
So that’s the current state of my thinking, on which I now declare open season. What’s problematic? What’s cliche? What can be improved? 
(And btw, let’s keep the above lore out of the Wiki for now, both because it’s still subject to change and because there’s likely to be a more comprehensive, organised lore-dump there at some point on Halassur, Nyryal, and the Abhumans that will include the above material in reshuffled form.)