The Illicit Invader Set seems to be glitched and it is currently impossible to transmog or put an ornament on the set itself. I questionably call this a bug because you can transmog other items to look like the set. Anyways I kinda wanted to bring attention to this because the titans got a really good pair of gloves from Xur and I wanted to be able to put a certain ornament on the gauntlets so I could match it to the rest of my guardian. Good luck fellow guardians and have a good rest of your day.