I hope the engrams work. I've gotten about 15 Legendary Heavy Weapon Engrams between the beginning of March until now. Not one Exotic. Out of 40 or so Legendary Engrams, not a single exotic. On the other hand, I got The Last Word, Hardlight and No Land Beyind as rewards from Roc in that timespan. Unfortunately, I had all of them. Xûr won't sell Thunderlord and cut me a break, so I'll just keep plugging away. Nightfalls, Raids, Engrams... None of it really works. It's pure luck. I got Gjallarhorn from Xûr on PS4 and I got two from VoG on Xb1. Good Luck and Happy Hunting!