Master all jobs quickly:
After finishing Border Forest, go back to it from the east side the one you exited from; do not bring any monsters. Rope your way across the pit, go into the opening in the trees at the top,t hen through another opening at the right. You will find four rocks surrounding a bush. Break a rock, then cut the bush to fall down into a room with Green Cores. These monsters give 2525 experience points each and appear in groups of two or three. They have low HP, but very high defense. First, fight a few battles and kill all your party members except for one. Have him kill as many Cores as he can before they run away. Use Chance Hit, Virus, or any other group attack spells except for Frost. For maximum effect, make sure the character has an attack power over 120 and has learned the Rogue skill Rapid Fire. This allows you to take out all the Cores in one hit. When the room is cleared, exit and reenter to find the Cores again. When a character has mastered all the jobs, revive another character and kill the first. Then, repeat the process. This is the fastest and easiest way to master all the jobs and will make clearing the Ancient Cave a breeze for Eldin.
Using two characters in the Ancient Cave:
In the Ancient Cave, use a Cave Disc and capture a monster that you want to use there. The monster can also assist you in the Ancient Cave. The best monster to capture is Cyclops Dragon, if you level it up with Power Source. Teach Cyclops Dragon with Octo Strike and you will be invincible. Battling through sixty floors will be a lot easier.
Best armor:
The Lucinia Armor armor is the best Armor that you can find. When the enemies damage your hit points, your HP and MP are automatically replenished, but sometimes it does not do anything. You will also see that miracle is being used. You can get the Lucinia Armor on the 36th to 60th floors.
Best weapon:
The Gaia sword is the most powerful weapon. You can find it on the 60th floor of the Ancient Cave. You will need some luck to get it. When equipped, the Gaia sword boosts your attack power a great deal.
Best shield:
The Divine Shield is the best that can be found in the game. You need some luck in the Ancient Cave to get it. It is on floor 59 to 60.
Best helmet:
The Divine Helmet is the best that you can wear. It is found on the last two floors of the Ancient Cave.
Best accessory:
The Egg Ring is the best one you can wear. If you wear it on your character, you can attack two times. If you attack with rapidfire, you can attack three times. Now, no one can stand in your way. You can find it on floor 59-60 or you can get it by killing the boss on floor 60, to beat the Ancient Cave.
Train Easy:
After you can enter the Ancient Cave, buy yourself a suit of Bronze Armor and the best weapon that you can buy at the moment, kill off your party members and get have the main character train as a Swordsman. Get him to level 10 and enter the Ancient Cave, if you can defeat the boss on floor 9, you'll get 6000 experience, make sure you have a providence because the monster on floor 12 will be able to do 80 damage to you. I was level 25 and it was doing 97 damage to me. Repeat this process to gain levels very quickly. It's also a good way to master classes, I've mastered 4 already.
Easy exp 20100:
20100 EXP In Ancient Cave...
In the Ancient Cave on the 17th floor is a floor boss called the Parasitic Cell, if you've learned Miracle Hit and are above level 23, you should be able to defeat it by using Miracle Hit every turn. It has 1250 HP so you'll be fighting for a while. If you win, you will receive 20100 EXP.