Actually she just described the basic costume layout while I designed all the details and extras, including the wings. She also likes the Magical Girl stuff, so in my mind, I was thinking Sailor Moon but mixed with a minor goddess of winter. Believe it or not, I had never heard of this Cirno character until just now websearching her. I see what you mean with the character's similarities though, especially the simple ice wings style.
I thought just doing large elongated diamond shapes would be a simple, lazy way to do it because they give the same feel as large tapering feathers on traditional wings, and she's got to look semi-angelic while also leaning into frost and ice themes/aesthetics, which is also why I wanted the dual-band rainbow halo look on her headdress. The original inspiration was actually wings made out of shattered panes of glass, so making them a little flatter looking was both easier and stylistically appealing as well.
But it just goes to show, there's rarely such a thing as an original idea. X)
Glad you like it and the glow effects though. Those are my favorite thing on any piece. Makes everything so atmospheric an aetheric.