Delightfully Dizzying Dresswear

Less so the amount of costume changes, though there are changes as character's spots in the world changes, but more so the shear amount of costuming for different races, different tribes, and groups, making two styles for one person because they have a long lost twin, etc. We've got the Wahan tribe, the Saram (& another), the Neathals, and more tribes with their own ways that may be similar, but also a little different due to their own beliefs/location.

Really on this list for Yoon Se Ri... but... this article by DianneP_Kim does a good job going over hers and other's styles, and the compilation photos are great to see them in one spot. >.<

When I look up examples and find this article on Soompi by hgordon.
... Looks like my job here is done >.<

I will always use whatever chance I can get to gush about Kudo Hina... so here we go again.
Her array of dresses and accessories along with her no nonsense attitude gave me, on multiple occasions, the urge to draw her. <3

When we first meet Si Teng, she is wearing qipao, but as she gets to know Qin Feng, her clothing becomes more modern and flowy, but just as effortlessly beautiful looking.
Bonus for Siteng and Qinfeng's alternate ending ep clothes here

A lot of fans like to poke fun at the fact Zhang Zhe Shu(ZZS) and Wen Ke Xing(WKX) are wanderers, as in travelers, as in not going home/having a home to go to, and not carrying any sort of bags for clothes and the like, somehow still have a new change of clothes at least once an episode, sometimes multiple episodes.
I'm a fan of loose and flowy, so ZZS's after Window of Heaven are definitely my favorite of the bunch, but the WKX and the others are nice as well.
One also has to pay attention to small details in their costuming. Small references in hair pieces to the past, color play between the two(ZZS &WKX), complimenting each other or pulling the other's color in their own clothing.
Bonus points for their Bonus Episode Ending Clothings

Ok... He's here cause I absolutely love his private eye/detective get up XD.