Collect the five armaments after the world is fused, then return to Isapolis.
Obtain the secret character Doll
To obtain Doll, one of the two secret characters, you must first get Nephi after visiting the entrance of Isopolis. Once you have done that, go back to the Corridor of Clouds and return to the entrance of Abraxus' Tower. Instead of entering the Tower, simply go to the right and examine the door you see there for Nephi to unlock it. Once you have done that, you must locate where a purple person is and examine him, after a brief scene, you will now have Doll in your party. Be sure to scour the workshop to get useful armor for your party!
After The Forbidden takes control of Vai and partially fuses Artania with the Black Rift, you can obtain the Sigil equipment (previously the Armaments).
1. Sigil Armlet: Go to the Desert of Black Sand located east of Polamaze. Make your way to the dungeon located in the south-east and defeat the boss to obtain the Arml
2. Sigil Armor: go to the Arena (where Xanadu previously was) and enter the Team Battle; make it up to the 9th battle, then opt out.
3. Sigil Blade: Visit Tradefair the quest for this piece. The Blade can then be obtained by defeating the boss of Draken Mansion.
4. Sigil Helm: buy in a shop right next to the clothes shop in Tradefair; it costs 100,000 GP and is the only item for sale.
5. Sigil Necklace: beat the boss on the bridge leading to Tradefair
Infinite cash and stat potions
Once you have Catalogues 2 and 3 you can buy and sell from them by traveling to an unmarked island on the south east corner of the world map. Talk to the owner and buy a few Eternias from Catalogue 2 for 30,000 and then exit out. Talk to the owner a second time and sell the Eternias to him through Catalogue 3 for 750,000 (profit of 720,000). You can do this to max your money at 9999999 in seconds and then buy infinite stat potions from Catalogue 3.