If you unlocked your havoc hidden appearance, the moment you unlock one of the other three colors it auto unlock it for vengeance now making it usable without farming for the main hidden appearance item. I currently have the 1000 kill and soon the 200 WQ on havoc and I have the red bulwark unlocked on vengeance. I was so happy to discover this after the patch. Was t like this before patch because I think we needd to grind two time before right?
edit: mainly for those going crazy fighting the boss everyday with no luck!