You've made it to the final region of the game. The monsters that you encounter here will be among the strongest in the game, but they will also provide you with a great number of experience points upon defeat. As the name of the region suggests, Maten is a large mountain which you must climb from the bottom to the very top. There aren't a lot of landmarks or significant features all the way. There are a few cave entrances, but none that must be explored except for the palace entrance at the top.
Since you should have six magic books at this time, there are only two more to obtain. One is patiently waiting for you on one of the bluffs, but the final book must be obtained by tracking down and catching one of the thieves. The thief will always run away, so his location cannot be pinned down to one place on the map. You'll need to rely on your crystal ball instead. Watch out for the flying Hawk Knights that occupy the mountain. If they can't reach you from where they stand, they will fly towards you to attack.
A: A Magic Book
As you make your way up the mountain, you will encounter many steps which lead to new heights. Some of them are useful, while others dead-end and don't provide you with a new path to take. You should thoroughly explore them anyhow, as one bluff in particular contains an important treasure chest. Inside this chest, sitting right out in the open, you will find one of the stolen books. Be sure to grab it before you continue on too high and have to backtrack to collect it.
?: The last thief
As you explore the mountain, you will occasionally spot another person roaming around. However, if you get too close to them, they will notice you and begin to run away. At that point, the music gets faster, and you must run to catch up to them. However, the enemies won't make this an easy task. They will happily slam into you and slow down your progress. You will only be able to catch the person if you manage to chase after him uninterrupted, so choose your path carefully. If he does happen to make it off the screen, you will eventually catch up to him further up the mountain. Once you nab him, he will inform you that the book have been stolen and the Chaos Dragon has awoken. He will then give you the only book he has in his possession, and beg you to stop the Choas Dragon.
B: Maten Palace
Naturally, your final goal is at the very top of the mountain. However, before you enter the palace, ensure that you have all eight magic books and the Dragon Scale. If you are missing any of these items, your trip to the top will be for nothing, and you will be forced to return an find what you are missing.
While Maten Palace has many floors, it's not necessarily much bigger than any place you've visit before. Naturally, there's a basement level that you can visit by walking to the left from the entrance, and if you do, you'll find a magic chest that restores your magic. Likewise, you'll find another chest on the second floor (to the right of the entrance) that does the same. Throughout your visit to the various palace floors, you will encounter many Hawk Knights. Be sure to thoroughly remove them instead of risking valuable health by trying to run past them. Additionally, it's important that you earn as much experience as you can while you attempt to reach the highest level of 15 at 7500 experience points. It's not entirely necessary to do so, but it certainly will help.
The final floor has several strips of burning floors that you must cross. While it may be tempting to use the Necklace to avoid taking too much damage, this will drain your magic, and you will want to keep your magic points as high as possible. On the other hand, there is no health restoration, so if you're low on health, you will have no choice. The best strategy is to attempt to gain a new level while occupying this floor. You can do this by walking back and forth between the second and third strips of burning floor. This will restore your magic and health with only a short distance to reach the last door. When you are ready, pass through the door to face the final boss.
Final Boss: The Chaos Dragon
Upon reaching the roof, you will automatically use the Dragon Scale to transform back into the Gold Dragon, and fly into the sky. You will approach the Chaos Dragon and begin the final battle of the game. At first, he only attacks with a single head. The head will wind back and forth trying to get a fix on you, and alternate between a flame breath and a scattering of smaller fireballs.
Your own attacks are limited to a similar flame breath with and a special fireball that you can spit by pressing . This fireball is extremely powerful, and you only get so many of them. The number you can fire is dependent on the number of magic points you possessed when you entered the fight. The most you can have is three. It is highly recommended that you save all of them for the second portion of the fight.
Continuously attack the single head of the Chaos Dragon in between his attacks, and fly left and right beneath him to avoid getting hit. Once the lone head takes enough damage, it will disappear, only to be replaced by two more heads. You must now inflict enough damage to both of these heads who attack independently from one another, but still try to hone in on your position. However, these two heads will be on a slightly shorter neck, and can't reach down as far. If you have any special fireballs, it would be best to use them on either of the two heads (the Chaos Dragon takes damage as a whole). Then continue to press your attack while avoiding his as much as possible until he is defeated. If you succeed, you will be treated to a rather short ending sequence. Congratulations.