Grey - Skin Butterfly girl?

I tried everything, and honestly I think I'm going insane. When I was a kid, I remember watching an amv of some kind that had this beautiful art style, and a grey skin butterfly girl, with long dark hair. I'm trying to find out what is the anime (or short? Or clip? Honestly idk) that had her. Ya'll are my last hope. Since it was an amv, it was several scenes of her, so here's what I remember (some things may be inaccurate):

• In her alien/magical girl (?) version, she had Grey skin, marks all over her body (it looked like butterfly patterns), long black hair, butterfly antlers and monarch butterfly wings.
• In some scenes, she was in space (?) Or at least, in the sky. I think she was the villain, i remember her fighting a very protag-like girl
• In one of the scenes, she's seen writing some runes in a sort of portal, and she's getting hurt doing it (using her own blood? I dont remember)
• She has a human version, she's just a normal school girl with long dark hair, she's also very serious.
• the art style resembles sailor moon/evangelion

I honestly can't seem to find where does she comes from, BUT I KNOW WHAT I SAW. Please reddit, do your magic, I beg Ya'll.