- Talk to Leepe-Hoppe. Answer his question affirmatively to get a cutscene.
- Battle each of the six prime avatars and collect their whispers. Do not return to the original NPC who gave you the quest. You will lose your whisper by just talking to them
- Instead, take the whispers back to Leepe-Hoppe to get another cutscene. You will lose your six whispers and receive a Key Item: Moon Bauble.
- Once you are in Inner Horutoto Ruins, you will need to go through the Three Mage Gate. Have a Red Mage, White Mage, and Black Mage stand on the corresponding colored circles or have someone who has the Portal Charm open it. The Moon Bauble will not open the gate.
- Alternately if you have started the Windurst Waters quest, Toraimarai Turmoil, you may enter Toraimarai Canal from Windurst Walls. Upon entering you may navigate to the Full Moon Fountain, however this trek is slightly longer then just going through the Three Mage Gate at Inner Horutoto Ruins.
- Take the Moon Bauble to Full Moon Fountain and defeat Fenrir Prime.
- Return to Leepe-Hoppe for your reward.
Note: You may now go back and do the other prime avatar battles again, turn in the whispers, and it will not affect your ability to fight Fenrir. Furthermore, if you want to fight Fenrir again, all you have to do is speak to Leepe-Hoppe for another Moon Bauble.
- Leepe-Hoppe wants you to take on Carbuncle's request to gather the six "whispers," then pay a visit to the Full Moon Fountain...