When you fight Lord Ravencrest, don’t do what I did and open with a one-shot on Latosius. The dungeon is immediately marked as complete and Latosius falls over dead, but Lord Ravencrest still attacks you (and will be immortal at 1HP), and Latosius’s corpse will teleport around the room as if doing its normal attack until it despawns. While this marks the dungeon as complete and the boss as defeated, you get no loot and no quest credit for it.
Please make Latosius immortal until he has done his little reveal and finished dealing with Lord Ravencrest.