The adopted daughter of Debonair, Nova is an unstable girl who often switches from affections to death threats in the blink of an eye. It is later revealed that she is actually a shadow of Shidou Hikaru’s heart, being her alternate ego; opposite in every way. As much as Hikaru is willing to die for her loved ones, Nova wishes to kill them all. Similarly, Hikaru hates herself for what she has done in Cephiro, making Nova love her very much.
Nova is an anime-only villainess created, not by CLAMP, but by Hirano Toshihiro. Her character design was made for a different anime which was never realized or produced.
I miss Magic Knight Rayearth. I hope there’s still a DVD of this somewhere. I never did get to see the ending of the 2nd season.