This quest will require harvesting OR possessing the above mentioned rares. Due to a bug that has been reported, you cannot possess some and harvest others when you reach that step. You must either possess ALL of them before reaching that step, or harvest ALL of them after reaching that step. If you want to take the easy route, be sure to have everything listed in your bags before you go talking to Nuniun. You may harvest them or purchase them, so long as you have them before you speak to Nuniun.
EDIT: As of October 13th, 2024, this bug is STILL in effect. Make sure you have the rares you need in your inventory BEFORE you start Step 6 to avoid needing to restart this quest in the series. You can mail the items from another character and you get the updates.
If you forget, just delete the quest and start over; if you have already harvested the mandible, it will stay in your inventory and will not make you repeat that step.
UPDATE: on 7th December 2024 I was able to buy rares from broker and harvest rare items at the same time and getting my update.
Speak to Enolyn Felwater of Nuniun's Scouting Party ( -448, 158, -798 ) Copy/waypoint -448, 158, -798. She will give you a travel bauble that will transport you to Nuniun.
Alternatively, travel overland through Shadeweaver's Thicket then use the rope line at ( -287, 157, 477 ) Copy/waypoint -287.20, 157.27, 477.20 near Vex Thal to reach Nuniun's camp.
Speak to Nuniun and listen to his story. If you did not do the tradeskill signature quest line from the Luclin expansion, Nuniun will ask you to make him one Three-Rockhopper Egg Omelet. You will be given the ingredients and can make it at the nearby campfire.
Note: If you have already completed the Luclin tradeskill signature quest line this step will be skipped.
Procure an intact shadeweaver mandible.
Find a recent shadeweaver kill at ( 172, 91, 132 ) Copy/waypoint 172, 91, 132. Not trackable.
Obtain the remaining materials to make the signalling horn for Niniun.
If you have a flight capability, it will be available to you after this quest and you should be able to fly back to the top of the cliff instead of using the rope or needing a Call-Of-Shade potion.