Need info on Rhyxali and Shaddonon

[Ezequielramone]

Long story short: I'm running a Tal'Dorei game where one of my players is playing a Ranger lizardfolk. He has a dark and confusing background and the result is that he casts spells with power from a demon entity. The way the character acts make me believe that Rhyxali is a good option/conection/ bond for him (found that she is princess of shadow demons).
I only found a bit of info on her on a Web Enhancement for Book of Vile Darkness (3.5 ed) and they only list her on Fiendish Codex II (3.5) and Demonomicom (4th) but no more info other than the layer she controls, Shaddonon.

Does anyone knows more about her? Can point me to the resourses please?
Thank you all in advance.

 

[Gradine]

I don't think there's much more than the resources you described, unless you want to go trawling through some DM's homebrew wikis.

Incidentally, when I first saw this thread title, my first thought was "This isn't a Pokemon forum..."

 

[Ezequielramone]

I kept looking and it seems that she is only mentioned in a Dragon Magazine about Graz't but no much more. That's cool I can makes up something.
Thank you!