>>49568568
I think it's interesting that Azmaya's SCoOW version of Kasen's design deliberately uses Onikasen's colors. In the manga where she meets Komachi >>49429347 >>49429359
She's also, based on dialogue at least, more or less facing herself again in a fresh way after fusing with the arm. I know it's artist headcanon, but ZUN won't really give us a continuation so I guess you could interpret this outfit change as her way of "fusing" into something better.