I've been working on some Luna stuff for a lil bit now [like about a week or so] and ngl her mirror world designs kinda slay. Like, I'm not a fan of the red in her unreformed mirror design when they legit have Nightmare Moon's armor for evil Luna color pallet stuff, but her hair serves absolute cunt in both forms
tbh a lot of Luna in terms of character design is really good imo, like you can look at her and immediately understand her extremely heavy connection to night and the such. Not even just from a color perspective but just a visuals perspective. The floaty wavy hair really screams 'space' to me even when it's just a silhouette, especially when she's corrupted into nightmare moon where her hair lools like a whole nebula of it's own. Like, even though I'm not a big fan of the whole 'floaty hair princesses' thing, it still sorta works for Luna specifically because of her status as princess of the moon/night.
Also, something from the prologue storybook [that's right we're going back to ep1 season 1] that I've always liked is the lighter outline color used on Luna's hair. It's just a very visually appealing thing to me. It sorta reminds me of the moons color actually, which works really well for Luna seeing as she's the princess of the moon/night and all that. Speaking of that title and the whole moon thing tho, Luna should probably have some sort of connection to the ocean and water? Since the moon controls the tides, and i feel like we associate water and ice with the moon alot collectively as a unit. It would also work well to contrast and complement Tia given her relation to the sun, fire, and imo agriculture. Water is how you douse fires and nurture crops, the sun melts permafrost and nourishes those same crops, the moon keeps the tides in check, forest fires prevent unchecked growth and safe soil for seedlings to grow, which circles back to water dousing fire to prevent unchecked destruction. They need each other to stay in balance, which is also true of Luna and Celestia. I don't think I can come up with a more interwoven duo of concepts, let alone one that hits the energy/vibe of two old pantheon deities, which imo the sisters are
