it's kinda dumb but why not:

I liked the idea of "night" and, for a name, "Nyx" immediately came to mind back when I made a character in... middle school? Who I still use sometimes since, frankly, I like her and she was sort of what the younger me aspired to be more like (more bold/assertive/confident etc...). At the same time I had made her a twin to another character I named "Vesper" for kind of the evening star/evening prayer aspect to it and Vesper sort of embodied a mix of stuff I didn't particularly like so much about myself (anxiety/stutter I used to have/etc...)

But a lot of people, back when I actually did write and RP and stuff, found Vesper /very/ endearing which ironically fueled some more confidence in myself -- at least insofar as starting to be able to find more kind things/positivity in the things I was insecure about. I ain't perfect now, but y'know, babysteps start somewhere.

That said Nyx, as that old character, sorta just embodied to me a desire to remember why I made her in the first place, and to continue working at my own issues to grow into the person I want to ultimately be. Since these two characters were demons originally and I was very excited about au'ra for the horns/scales/tails/limbal rings, I ended up naming my au'ra after that specific character. So it's a little bit of a personal message intermixed with just "au'ra kinda look demonic and that's fitting."

"Netherflame" was literally just trying to work out something like "a fire that burns cold", but also kinda worked with voidal thematics somewhat back when. And was also just kinda "what would Nyx, if given the agency, choose for her last name" and she is... edgy isn't quite the word, but like, she's a person who would pick something edgy. (I guess like, edgy/tough/spiky and rough on the outside, with a softer more pastel inside if that makes sense)

Basically a mix of a personal message + I'm jus a chick that likes metal/black armor/demons/big swords and red a lot.

it's better than my ESO character whose name is just Brutalika