You must have completed all other Mission Quests in all other areas to receive this quest.
Ascend the elevator in the Protectors Hall and speak with Lavirintos.
The Oath Stone can be purchased from Ophenes or Perena, who are in Caps and Straps along the Divine Road in Sanctum. It costs about 4 million Kinah per stone.
Take the stone to Jucleas
and have him perform the ritual of affirmation.
Report back to Lavirintos
and claim your first piece of the Miragents Armor!