Just say its interesting then?
I was doing work on Oriana Thompson, the idea was that it would eventually lead to why she chose her magic name. I believe Lorenzetti, the older nun who handles her, called her a sinner/untouchable. The elements and the colors reference the magic she wields. Unlike Birdway, her magicks are unstable and therefore primal in form so she fought like the fury of nature personified.
Please don't tell me this is a development where we learn Kuro is actually a flat-chested girl posing as her dead twin oni-chan. O.o
Sorry if I just ramble. I'm on a writing slump right now.