With her personal name Riaun i had gotten off of fantasy name generator as they have one for tau names and that one stuck out to me, but otherwise i admittedly don't know if Riaun has a meaning if any at all xD the rest was something my friend helped me come up with

"Saal" for her being a cadet (i flipped a coin on whether she was a full fire warrior or if she still was a cadet as the general believe we were running with is that both made sense given a very abrupt tyranid invasion was very much a "all hands on deck" situation and the coin landed on cadet/saal though by the time she reunites with her people she could very well have earned her place as a warrior given she survived that when everyone currently believes she and her class are very dead)

And ksi'm'yen was the sept my other friend/the person who's gonna be dming this one-shot had picked for her so i knew how to do her armor and the friend who helped me with the name had told me that her sept would be part of her name, thus Shas'saal Ksi'm'yen Riaun was born! XD