Sorry friend- I didn't read your intent right. It's not taboo for a woman to be topless, but not even men walk around town half dressed if they can avoid it.

She wears normal clothing when she's out and about. When not active the black star just looks as if someone had carved everything out. It turns into an infinite vortex when she summons a spirit through it, and the energy burns through organic material, just like how regular stars damage the earth. Too many nice shirts have the star burned clear through them.

She loses the shirt when she's expecting a fight. Besides then, she's got quite a reputation among mages, almost mythical, and she goes without a shirt when she wants to announce herself.

What kind of wings are those that hold up underwater?