Black hammer will still be able to output more DPS while it's ammo lasts. Let's not forget how much time BH saves on the devil walker.that thing used to be looooong, and BH makes it easier than anything. Whilst FB does make clearing adds easier, i think the other nerfs will combine to reduce fatebringer's effectiveness by increasing the effectiveness of other guns, combined with the HC nerf. Necrochasm will be a strong contender now that Gjallarhorn may not take you exotic slot 100% of the time. Icebreaker works in a similar way also, especially in the abyss. Scout rifles roll with firefly, and scout rifle pve dmg was increased 5‰,so this may encourage scout rifle firefly instead of HC.