I don't dislike his FS costume outside of the white zipper (scuba diving suits are great!). It's the SP one that makes me the most. Edit: And the preponderance of black across both programs.
I am hesitate to say that maybe “black” is intentional, maybe black is Nathan BOI's favorite color
Also, there is a "hidden" concept of great figure skating costume designs (if you trace those big name superstar skaters' costumes, it is not that hard to identify). That is, make it as a pack for a season's SP and FP. it is connected in subtle designing aspects.
For Nathan's SP and FP, the obvious "preponderance black" connection. and ofc the overall second-skin type of fit (and half hand cover sleeves). And that big shining thingy. in short, it is a white strip going down his chest/front and in long it is that ZIPPER going down his back.