No particular information was given by CLAMP, but they did design her.

<ChunHyang> She outta earshot yet?
* Asuka returns, panting.
<Asuka> I locked her out of the house.  It should be
        fine as long as we stay quiet.
<Sizer> She seemed a nice girl.
<Suu> On the same token, you're a nice person too,
      Sizer.
<Sizer> But I....!
<Rei> rika is giving us the "save it for the VoH char
      profiles, dammit I'll have nothing to write in the 
	  Pandora's Box Char Profiles" look.....
<Alice> Are we going to do that?
<Sizer> If so, I should be nice, because I don't know
        what Nova will say about me, then.
<Rika> rika's shaking her head.  I think she's making
       Mark-niisan do it for her.
<Sizer> probably in exchange for providing
        translations from which a special VoH fansub will
        be created for the CalTech Anime Society.  Figures.
<Alice> rika's giving us the "hurry up" look,
        guys....
<Satsuki> So Nova.  She's this girl.
<Alice> And she has a Mashin named Regalia.
<Asuka> Isn't that a Buick?
<Rei> Regal.
<Asuka> Close enough!
<Alice> I thought there *WAS* a Regalia somewhere.
<Shinji> Maybe in Japan?
<Asuka> I'm not familiar with Japanese car names!  I
        didn't even know about some of them until I saw the
        car names list!!
<Suu> But back to the point... does she do anything?
<ChunHyang> She casts fire spells.
<Asuka> And she likes to rag on Hikaru.
<Shinji> NigechaDamedaNigechaDameda........
<Asuka> There goes BakaShinji again....
<Satsuki> But she does have a reason to do so...
<Sizer> Fukushuu......
<Alice> Now that I think about it, Nova and Sizer-san
        have a lot in common....
<ChunHyang> I think it's just that aspect, dearie.
<Alice> I guess. ^^;
<Sizer> After all, I don't have pointy ears nor a
        catty personality.  I hope....
<Suu> I don't see ears but I see wings =)



(so anyway, here are some spoilers.)


<Asuka> So why does she like to rag on Hikaru.
<Sizer> Revenge.... what a sweet-sounding word......
<Satsuki> And if I were in Nova's shoes, I would be
          kinda pissed off at Hikaru too.
<Asuka> But why Hikaru?
<ChunHyang> Because Nova is Hikaru's shadow, a
            figment of Hikaru's imagination, a piece of
            Hikaru's heart that regretted killing Emeraude
            that was left in Cephiro all by herself......
<Asuka> WHAT!?
<Satsuki> What, you didn't realize that?
<Asuka> No!
<Shinji> Now the "I was born for Hikaru" makes
         sense.....
<ChunHyang> And she was lonely without her better
            half, and Debonair found her, and basically
            brainwashed her to think that if Hikaru died,
            she would be happier.
<Rei> But Nova finds out the truth in the end.
<Satsuki> Right, and that's another example of good
          defeating evil that we see in RayEarth 2 anime.