Brigade Layered unlock?

I've looked up and down the internet to find this. Some say complete all the blue star quests at the Arena (done). Some say complete all LR/HR Arena quests (done). Some say Lunastra questline. I've gotten a dozen different lines, and none of them seem to work. I just want my big hat.

ETA: I'm past Fatalis. HR over 300 MR over 200.