Mir is standing behind a Raen Au Ra with long white hair that is wearing a pure white and gold robe and wields a lunar-themed astrologian weapon.
Shurelia from Ar Tonelico. She has very long white hair and wears a white skinsuit with gold accents that look like valves for an instrument.
I decided to make another character from #ArTonelico: Shurelia.
Going from what I've established with Mir (parents most likely from the Steppe & Thavnair), I think she's going to show up in Radz-at-Han. In this world, she's Mir's sister.