Reach the Vandalier secret class with Ash, and finish the game to get an extra congratulatory message at the end.
Chaos Key
To get the Chaos Key, you need three items they are the Macroman, Tarot Card, and the Ramen. The Macroman is found in the NW corner of Ygdra Canaon. The Tarot Card is found at Basil Gate in the SE corner, there is an X made of grass. The Ramen is in the grate on the front car on The Magical Train. Go to Kerachi Village, go to the tavern and talk to the colector.
Earth Key
Talk to the young man in the tavern at Yuzu. He tells you that he dropped a weird fruit in a plus sign bog. Pick it up and give it to him. You will then recieve the Earth Key.
Gain Levels Quickly in Chapter 2
In the battle of the castle ruins in Chapter two (before the fight with Magnus and after the ambush at the swamp), there will be two healing circles and two elevators. First, stock everyone up with Mage Oil before going into the battle. When you enter the fight, kill all the monsters in the level, but don't go anywhere near the temple!
Instead, have Sara stand on one of the circles and begin casting "Mystic Shield" on herself over and over. It takes six casts to raise one level. Raise her to level 49 (easier said then done!), then have Huxley stand on the cirlce beside Sara and cast Mystic Shield on her. He will jump up to level 46 or so. Do it a few times more to get to level 49. As for the people who can't cast it, have them use the Mage Oils, it works just as well.
Important: Do NOT do this trick with Ash, or you will encounter problems later on in the game!
Heaven Key
With all five keys, talk to the wierd man in Glasgow City. He will give you the Heaven Key.
With all of the prisms, go to the Dojo, the Dojo Master will advance Ash to the class of Vandalier. Now you can see the true ending.
Logos Key
After saving Leena in the Tsukue Plains, return to Frontier Village. Talk to the old man in the Tavern. You will learn that the is something in the center of the lava pond. Go to Smoking Bones Cave, search the center near the Salamander with a flying character. That is where the Logos Key is.
Mana Key
At the Prison Fortress, search the ground neat the gate. You will see a small crater, that is where the Mana Key is.
Nova Key
After killing the Death Ant in the dunes, talk to the woman in the tavern and she will give you the Nova Key.
Tip
Do not go to the mystic battlefields right away. Let your team level up and have more people. This will make the battles easier.
Vandalier
To have Ash become Vandalier, you must find six keys. These will transport you to a mystic battle field. To be transported, equip Ash with a key. Enter the Dojo then leave, you will be asked if you want to be transfromed, choose it. You must get the prisms in the treasure chests to become Vandalier.