The female version of Byleth's promote class the Enlightened One, as seen in Fire Emblem Heroes as a legendary alt.

I've heard plenty of people call this design a mess, especially compared to the male version which feels like a fairly tasteful religious uniform, but I think the female Enlightened One design has grown on me since release, especially now that Legendary Female Byleth exists. You probably didn't notice it, but the Heroes design differs slightly from the original version in Three Houses, mostly with the purpose of cleaning the outfit up and making it a less jarring contrast between the elements of Byleth's original design and the new ones.

Whenever I don't post for a long time, I feel obliged to explain myself; in this case I have been working on skins in the background, but I tend to forget to post them. I'll gradually catch up with any I have missed, although I can't guarantee steady uploads.