As you enter this place, head south and in the next area, head east as far as you can and grab the Treasure Chest here to get a Diamond Mace, which is a pretty good Staff, so, use it if you wish if anyone uses Staves that is. Then, head southwest as far as you can go to find another Treasure Chest, which holds a Hellfire, then head east and enter the door here and go down the stairs. On this floor, head north and grab the Treasure Chest here to get another Hellfire, then head east and grab the Treasure Chest here to get a Notus. Next up, head south and get the Treasure Chest here to obtain a Cat Claws, which is guarded by a Blue Dragon. BE CAREFUL, as he is VERY POWERFUL. If you've been training, he should go down pretty fast, but if not, have fun. Afterwards, if anyone is using Knives/Daggers, give this to them, as it's the best one in the game.
Afterwards, head east as far as you can, then go north and enter the door here and then head down the stairs. On the next floor, just follow the path here and cross across the waterfall near the door, which will damage you for 1 HP per step and continue down the path until you reach a Treasure Chest, which holds a Rune Axe, but it's guarded by a King Behemoth. Don't worry, he's not that hard. After the Battle, give this to Gus if he uses Axes, otherwise, Leon if he does, then, continue west across the waterfall and then on the bottom part of this area, go behind the waterfall here and when you can't go any further, examine the area to find a hidden magic shop! If you want anything here, buy it, otherwise, leave this place by going through the door to the far east and heading down the stairs inside.
On this floor, head north and get the Treasure Chest here to obtain a Backstabber, then continue north and enter the door here and in this room, grab the 3 Treasure Chests here to get a Holy Lance, Aegis Shield and a Dragon Mail. I suggest you give the Aegis Shield and Dragon Mail to Firion or whoever else needs them the most and if anyone uses Spears, give them the Holy Lance, which is the best one in the game. After this, exit the room and head east and open the Treasure Chest here to get a Yoichi's Bow, but it's guarded by a Red Dragon, which is also VERY hard. Afterwards, give this to Maria if she uses Bows or whoever else uses them if anyone, as it's the best one in the game. Next up, head south and enter the door here and then head down the stairs.
On the next floor, just follow the path and grab the Treasure Chest you come across to get a Hi-Potion, then continue on and get the next Treasure Chest to obtain a Protect Ring, which is only good for the protection from K.O. Status, otherwise, don't use it, as it's rather weak. After this, continue on and open the next Treasure Chest here to get another Hi-Potion, then continue on and enter the door you come across and go down the stairs here. On this floor, just follow the path and when you come to a teleporter, step on it to enter Pandaemonium, THE final dungeon in the game… get ready…