Free Potions in World II:
In Kelb town, enter the Inn. You'll find a man sitting on a table talk to him then sit on the chair on the LEFT (NOT in front of the man)! He'll give you some kind of wine then he'll give you an after meal gift of 8 Potions! You can repeat this to get 24 potions.

Brave Sword or Chicken Knife:
Before venturing into the Cleft of Dimension, return to the Town of Mua.In the southwest, a door that was previously locked is now open.Through the door is a hidden path that will lead you to a man.He will offer to give you a Brave Sword or a Chicken Knife.The Brave Sword will get stronger as you win battles and the Chicken Knife as you run from battles.

Alternate Tycoon Castle Scene:
In world one when you get the Hiryuu ( Dragon ) you have access to Tycoon Castle. If you go, there's a scene involving Leena and Faris where Leena suspects Faris may be her long lost sister, Sarisa, and Faris denies it. But, if you wait until after you get the airship it's an entirley different scene involving Leena's childhood.

Easy Experience and Levels in World 2:
To get a relatively easy 2500 experience points and 5 AP in the second world, go to the Sealed Castle, the one with the legendary weapons. The random moster in there, an undead-looking dragon, is very powerful and is probably not meant to be defeatable at that point. However, if you have a character that can use the Control action you can defeat him with litle or no damage.

He might resist being Controlled a few times, so perhaps multiple, fast characters with the ability might be useful, but one was enough for me. He might get some attacks in before you Control him successfully, though, so prepare to heal your party and possibly cure them from the Zombie satus effect.

Once you successfully Control him, he has two attacks you can make him use on himself. DON'T make him Attack himself, or he'll break out of your Control. On that note, don't let any of your party members attack him either for that same reason, plus they wouldn't make much of a difference anyway. Instead choose him Flame attack, which will deal 4999 damage to himself! And since it's magic, he won't break your Control. He seems to have about 20,000 HP or more, though, so it'll take five Flames to kill him. This worked for me consistently, but just remember to save often in case things don't go your way.

Defeat Catastrophe easily:
Before the battle with Catastrophe, equip a Wall Ring on one of your characters, and cast Float on that same character. Then, go into the battle. Whenever one of your characters is Floating, Catastrophe will always use Gravity100 to ground that character. However, because that character has a Wall Ring, the attack will be reflected back at him. He will continue to use Gravity100 for the entire battle, allowing you to use any attacks you need to beat him without the fear of being killed.

Avoiding the final battle:
If you don't want to fight Neo Exdeath (the transform of Exdeath) you need to use the command Mix (an ability of Chemist Job), then mix the items Maiden's Kiss & Holy Water to create Kiss of Blessing, then give it to Exdeath and kill him, he won't transform to Neo Exdeath & you can see the ending.

Make the game impossible:
In world two with your submarine, enter the castle with the legendary weapons from the right. Then exit. You can't get to your submarine thus making it impossible to continue the game.

Killing carbunle in 1 hit:
If you have a mystic knight on your party, cast Fire 3 and in the next round hit Carbuncle with it. It will not show any damage, but it will kill him.