Currently, it is literally impossible to get the Harbinger seal. In order to get the seal, you need to complete the Lunar Badge by acquiring all moon/shadowkeep items. But at least four of the guns needed are completely bugged, including but not limited to: One Small Step (essence of rage), Dream Breaker (essence of servitude), and personally Apostate (Altars of Sorrows), and Heretic (Altars of Sorrow). **Essence Quests: ** The bosses needed for the unique items to complete the specific quests mentioned above do not spawn in no matter what. Other bosses that are always supposed to spawn in sometimes do not, like the High Conductor for the Deathbringer quest. **Altar Of Sorrows:** While the event itself runs fine, aside for the boss always being Phogoth, the weapons do not rotate. Every time I have beaten the final boss, I always get a blasphemer no matter what. Without these guns, it is impossible to get this seal, which is a real shame considering the amount of time I and others have already put into getting it. Crossing my fingers that these get patched. This is by no means a complete list of all the bugs in Beyond Light with the Harbinger seal, but just the ones I have experienced. Pls fix :,) EDIT: You can actually get all of the essence weapons AND Altars Of Sorrows weapons from Pit of Heresy! For the Altars weapons specifically, you do need a Hymn of Desecration but those are pretty easy to get. Thanks to @EWayne90 for pointing this out!