Imagine I was so used to drawing Gurei with a longer hairstyle to signify a timeskip from his first look, he having a small mullet even. This was the replacement design of the 2nd one, and was prominent during 2007-2009.
Having a brighter palette of blue/white/red compared to his black/grey/red scheme from his past two outfits, I made it so to symbolize him getting rid of the cursed blade he used to wield (the one in the 1st design), but still have curse leftovers (forgot the exact term but yes)
[EDIT: Added Bluesky / Twitter links to show ye olde art references for this look!]