Neekin began through happenstance. I had written a fantasy story entitled "The Test of the Pearl", about a young novice, who, at the story's end, breaks from her religious order to become a wanderer.
The only significance to the thing was that I actually sold it (in fact, I think it was my first paying sale!) Well, not wishing to let a good thing go, I instantly started writing other stories about the lead character who was, of course, Neekin!
Quickly, other things began coming together, a coagulation of ideas that had been kicking around in my head.
Perhaps the most significant at the time was Neekin's somewhat libidinous sexuality. You see, this was written back in 1994 (published in 1995). At that time, there was still the archetype of the assexual -- even anti-sexual -- sword & sorcery heroine, or female characters who would lose their skill/power/whatever the moment they lost their virginity. In other words, while Conan could play around, his female counterparts were curiously celibate. So I decided Neekin should be a rebellion against that (arguably sexist) cliche. As well it was intended to reinject a note of tawdry titilation into the increasingly staid, respectable genre that S&S had become -- a return to its pulpy roots.
The idea of Neekin's bisexuality came about simply because it had been used in "The Test of the Pearl" and I realized it actually opened up story possibilities, allowing Neekin to have relationships with men, but also allowing for the kind of standard Conan-like liasons with slave girls, princesses, and damsels in distress. There are Neekin stories that could not have been written, plot-wise, if she had been an exclusively heterosexual character (or a man, for that matter). But what becomes truly fascinating about all this is that now Neekin seems like a cliche!!!
A couple of years after Neekin first saw print, TV gave us "Xena: Warrior Princess". Here we had a tough, capable, S&S heroine, who was perfectly capable of being a sexual being, and did not see the two as a contradiction. What's more, as the TV series has progressed, there's been an increasingly overt subtext of bisexuality. I don't for a minute believe Xena was in any way influenced by Neekin, but I think it should be noted that Neekin was clearly not influenced by Xena.
Other aspects that went into Neekin?
The religious upbringing as a "Warrior-Priestess" helped explain Neekin's fighting skills, without avoiding the fact that, realistically, most of the men she'd encounter would technically be stronger than her. Neekin's prowress is her training and nimbleness. This also gave Neekin a religion: while Conan has his Crom and Elric his Lords of Chaos, Neekin believes (at least somewhat) in the Spirits of all things, animate and inanimate. This led, logically, to Neekin being a vegetarian and disinclined to kill an animal if it can be avoided. Her religious upbringing, though she has obviously grown more secular, still influences her in some ways, such as her abstemiousness when it comes to alcohol.
Having grown up with the Tarzan novels, and the dramatic contrast therein between the city mouse-country mouse, I also wanted Neekin to be a barbarian. This had also influenced Conan, but seemed less and less prevalent in other fantasy characters. Even then, Conan came from his own society, and the contrast between one pre-industrial society and another isn't always obvious to a 20th Century reader. Therefore, Neekin had to be truly feral. But in "The Test of the Pearl" it's established she has a family, and was even sent to a religious school. The solution? Neekin was an orphan, adopted by her "family", who quickly bustled their unruly charge off to the temple. Neekin herself is unsure even of her true background. This of course opens the way for "revelation" stories, if the mood strikes me.
References to Neekin's mis-matched eyes were added subsequent to the first story, since I felt the character needed something distinctive.
The tropical, quasi-African setting apparent in many (though not all) Neekin stories was a throwback to to the old pulp days. Most fantasy and sword & sorcery these days is set in vaguely European milieus, but I always felt there was greater mood and atmosphere inherent in the sweltering jungles, desert empires and lost cities of Burroughs and Howard. Of course, such early stories were often marred by racism, which I hope no one will attribute to Neekin and her adventures. A number of the stories acknowledge the contrast between Neekin's white skin and the dark-skinned people with whom she (sometimes) mingles, but not in any way to attribute a superiority/inferiority to one or the other. It merely emphasizes her outsiderness. Neekin has romantic trysts with people of various races, something earlier fantasy writers would not have countenanced. In fact, the Neekin stories are among the only fantasy stories that I'm aware of currently being written (even professionally) in which non-white characters appear at all! Not that the Neekin stories make any great pretensions at social relevance. These are, fundamentally, intended as escapist entertainment.