Fatebringer definitely isn't weak. While there are a number of weapons with 331 attack that will do more damage per shot than FB, the mag size and Firefly perk still makes Fatebringer an arguably better weapon. Word of Crota is an entirely different story. I got it after I had already been using FB, and the only time I really run it is when the Nightfall has Void Burn. Really disappointed with WoC.