Destiny 2: How to get Hawkmoon with random rolls and the exotic catalyst

Ready for the Destiny 2 Harbinger quest? Hawkmoon was my favourite gun in Destiny 1, so I was pretty nervous when Bungie announced a reworked version was coming to Destiny 2. But I needn't have been—the redux version of this exotic hand cannon is a monster, and much better in PvE than the original, which was mostly renowned for its PvP prowess. If you haven't got it, here's our guide to earning the base version of the Destiny 2 Hawkmoon exotic. 

I say base version because when Hawkmoon originally...