This is Sailor Makhai in her final form which is called "Ascended" for my pre-Solar team. Like the Sol Senshi's 'Eternal' form, these senshi are still referred to as their traditional sailor names even in these final forms.
Sailor Makhai is the youngest of the Ghya senshi who can all be seen in their first form here: [link]
Her planet was thrown out of its orbit when her sun went nova. It settled into orbit in the reformed Sol System and is now known as the dwarf planet Eris. Base from *leichan