The Aureole Ruins, also called the Sealed Area, is the final dungeon that lies below Grancel Castle. There are four descending levels that are reached via circular lifts. It is here where the Aureole and Colonel Richard is found and where the final battle takes place.
Joshua and Estelle are led into the Treasury underneath Grancel Castle by Queen Alicia where they are shown a sealed door. The queen produces a spare key which she uses to open the door leading into a room with an elevator. Joshua walks onto the elevator platform and inspects the control panel, learning that a special quartz is needed to activate it. Professor Russell, followed by Tita and Agate make a sudden entrance. Joshua soon explains their predicament and the Professor explains they need a card key to access the lift. He slides a small cable into the card slot, mentioning that the control panel is an early model and does not contain a failsafe. Suddenly, a Royal Guardsman appears and tells the group that a division of the army has arrived at Grancel's main gate. Queen Alicia stays behind as a result while the rest of the group takes the elevator down to the ruins. Once there, they decide to split up into two groups.
Once decided on the members of each group, they continue on to explore, descending deeper into the ruins and encountering numerous mechanized enemies along the way. In the 3rd level Hall, the run into Captain Amalthea. She taunts the party and tries to prevent them from reaching the colonel and calls upon two ancient mechanized creatures. Amalthea is defeated and Estelle gets Sieg to call the other members. Professor Russell explains they are probably at the half way point. The group prepares themselves and continues their exploration. Descending from the fourth level, they reach what is the bottom of the ruins and come to a large set of stairs. Here, the group rests and prepares themselves for the final confrontation.At the end of a hallway, the party arrives in a large room where they see Colonel Richard with the Shining Ring, the Aureole. The colonel explains to them about Sept-Terrion, the heavenly treasures and the Aureole as well as revealing his plan. After some talking, the fight with Colonel Richard begins. After the battle is over, what appears to be an Orbal Shutdown occurs and an automated voice is heard. A massive door opens in the room and the Ring Guardians emerge. They battle the Ring Guardians and the final form of Reverie and defeat them. Exhausted, the group is barely able to move when suddenly the Ring Guardian activates again and is about to hit Estelle. However, Colonel Richard intervenes and saves her and sacrifices himself to repent for his wrong doings. Cassius shows up at this time and knocks the arm off of the machine, releasing the colonel. Another fight with Reverie ensues and again, is defeated.