In order to get step 8, you need to be able to speak the orcish language.
Kill the Aqua Goblin Oracle (level 30^^^) ( 785, 50, 220 ) /waypoint 785, 50, 220 to get the brooch to start quest. Only 1 character may loot the brooch, and the HQ is not shareable, so you will have to kill the Oracle multiple times to start the quest for everyone in your group (respawn is 10 minutes).
One of the chess tiles ( -787, 101, -16 ) /waypoint -787, 101, -16 has a harvestable loose stone. Collecting it will trigger a trap, spawning four linked 34^ triggered guardians. If you looted the key from Zannas of the Arm (previous step), it will deactivate the trap and they won't spawn. You will always receive Tessa's Hidden Notes for Zannas regardless of if you kill the triggered guardians or not.
Enter Crushbone Keep. Slay four clerics of Hate on the second floor in the Hall of the Magi ( 70, 25, -36 ) /waypoint 70, 25, -36 to obtain the cleric helms. Most of the other mobs in the room are place holders for the clerics of Hate. Clerics can also be found in the Emperor's Chambers ( -13, 22, 31 ) /waypoint -13, 22, 31. The Oracle of Hate does not work. You may have to clear room a couple times to get all 4 to spawn.