You can only get this from Sublime engrams on the Playstation.It took me some grind. Ia lso have the exclusives for the Hunter and the Warlock, but i still miss one 320 ghost and a 320 cloack and a 320 armband. Sadly my friends stoped playing and i couldn`t do any challenge in the past 4 weeks. And seriously, after this last weekly update , i doubt they will ever come back.