You have met with the Nu Mou, who have agreed to discuss your request for the stone scepter.
This quest is available if you have completed the quest A Visit to the Nu Mou.
Starting the Quest
Talk to Wyd Aenc in Il Mheg to begin the quest.
Speak with Marn Ose
Go east and attune to the Aetheryte, then go to the quest icon on the map and talk to Marn Ose.
Slay Moss Fungi
Leave the cave via any of the three exits (one of the exits is at the end of the very narrow path on the map) and go to the orange circle on the map. Look for the quest icons on the minimap to find Moss Fungi. Slay them until you have two Moss Fungus Legs.
Deliver the Moss Fungus Legs to Marn Ose
Go back into the cave and go to the quest icon on the map. Talk to Marn Ose and there will be a cutscene. You were asked for a pair of Moss Fungus Legs, so the correct answer is 2. You will now be able to talk to Marn Ose to repair your gear.
Next Main Scenario Quest
After you complete the quest, talk to Ys Gyuf to accept the next quest: Spore Sweeper.