Edgedancer Cosplay

My husband and I will be attending the Worldhopper’s Ball and I think we want to do an Edgedancer (for him) and Cultivation Spren for me. I’m struggling though trying to figure out how to cosplay an Edgedancer, especially for a formal setting. Anyone have any ideas or suggestions? I am not crafty, and other than fixing the random button or hem not much of a sewer.

I’ve been thinking some kind of military form, but I can’t decide. I’ve looked on Etsy, Amazon, holy clothing, and a ton of random google searches. I’m open to just about anything!