Step one of this quest is not completable: It requires you to take legendary engrams to be decrypted by Master Rahool in the tower. The problem seems to be that all legendary engrams are now instantly decrypted as you receive them. You can purchase engrams from Rahool for legendary shards but these do not count towards the quest progress ether. I am very annoyed as I have the skin for the gun rewarded by the quest but it is impossible to get the gun. I am sure I am not the only person experiencing this bug. Please comment if you are too.
Hi. Thanks for your report. You should be able to find the engrams on other destinations that do not decrypt.