You will arrive in the town before Gulse Castle at the break of dawn. The first door (A) that you come to contains an unusual occupant; a man who will only offer to send you back to the previous stage. If you say "YES" to his proposal, he will return to you to stage 7. Assuming you have the Wizard's Soul from your fight against Viser's daughter, you do not need to return.
Continuing on, the next available door (B) contains a Medicine shop. You are well advised to spend a lot of money on yellow potions here to stock up. You only need 20 metal once you are inside the castle, so feel free to spend the rest of what you've saved up on some potions. Beyond the medicine shop, you will find the Inn behind the next unlocked door (C). If you are low on health, it's not a bad idea to stay over.
After you walk far enough into town, you will arrive at the entrance (D) to Gulse Castle. However, you will not be granted immediate access. First, a man will test you by asking for proof of your identity as the Prince. The Gulse Scepter will provide such proof, so answer "YES" when he asks to see an item in your inventory. You will then be allowed to proceed inside.
You won't encounter any new enemies in this fortress, but those that you do encounter are strong and should be dealt with carefully. You begin at the left end of a long hallway. After you proceed to the right a little bit, you will have to use your mace to break a passage through the bricks. Switch back to your sword so that you can deal with the snakes a little easier. When you see a Hyper Armor, you are about to stumble upon an invisible gap in the floor which leads down several levels.
The truth is, there is no real incentive to follow this route unless you are determined to purchase the Light Saber for 700 metal. Since a better sword can be purchased for only 10, you can skip this route entirely. For those that are curious, you can find an informant behind door (I) and a chief of the town behind door (J). Doors (K) and (M) will automatically warp you back to the beginning of the stage (which is handy considering how far from the entrance you've strayed,) and the shop which sells the afore mentioned saber is behind door (L). (It is worth pointing out, however, that the hallway which contains doors J and K is actually a good place to wander back and forth in an attempt to collect experience points and reach Class A.)
Assuming you fell down the gap from the main hallway, immediately jump back up and continue heading to the right. Watch out for the Hyper Armors and the Wheels that occupy the right end of the hallway. When you reach the bricks at the far right, jump up through the invisible gap in the floor to break the bricks from underneath, and create a hole for yourself to jump up through. There is a door (E) hidden in the left corner of the bricks which contains a Spell Book shop. Unlike certain previous levels, you are not required to have any spell books with you to complete the game.
Continue to break bricks so that you can escape through the left wall. Ignore the visible passage up through the ceiling and continue walking to the left. Eventually, you will reach a door (F) where you will find a shop selling the Platinum Armor for 900 metal. Once again, there is an even better set of armor available for a mere 10 metal, so you are not advised to purchase this. You will come to a passage near the ceiling above bricks. Beyond this passage is a door (G) that simply returns you to the start of Stage 8. Instead, jump into the ceiling near the left side of the passage, and you should pass up to a small room above.
In the room above, carefully break some of the bricks to the right of the shaft in an attempt to jump on top of the column to your right. From the top of the column, continue to break bricks overhead until you can reach the shaft and jump up through the ceiling to the next room. In this next room, you can ignore the right side (the door is locked) and simply break bricks over your head in order to access the next shaft. Jump up through the ceiling.
You are now in a new hallway. All you must do is proceed to the right over the uneven floor, and jump over the gaps from one statue to the next. Wheels will have a tendency to appear over head or behind you. If you continue moving to the right, they should not be able to interfere with you. Eventually, you will reach a small section of bricks with a passage along the top. Walk through it and drop to the floor below to find an invisible gap.
In the next room, drop down to the floor to the left and find the next invisible gap. You will fall down through a shaft to the floor of the next room. You must be careful in this room. It is possible to trap yourself in here without any means to return. Break the bricks over your head very conservatively. Leave Kein something to jump off from in order to reach the hole in the ceiling and return. Your goal is to break enough bricks to access the door (N) to the right. In here you will find the Extra Armor, the best armor in the game, for only 10 metal. Purchase it, and then prepare yourself for a long return trip.
Jump back up through the shaft to the room above. Break enough bricks in the wall above the floor to jump up and climb back up to the hallway above. Again, break only as many bricks as you need to leap up to the passage near the ceiling, and proceed to run all the way to the left, avoiding the Wheels as the appear throughout the hallway. Once you are at the far left end, you will find the invisible gap to the room below. Dropping down, you will need to break a passage through the bricks to the right, jump through the wall to the floor below, and then back to the left to access the hole that leads to the room below. Again, break a path through the bricks to the right, in order to break the lowest bricks and return to the left, over the column, and to the hallway below.
You should be back in the first hallway between doors G and F. If you are in need of health or medicine, you can return to the start of the stage by using door G. Otherwise, walk all the way back to the right side of the hallway in order to jump up through the hole in the ceiling that you passed by earlier. You will arrive at a familiar site; a room with three levels patrolled by three spiked bars. But this room has a twist. The bars move much faster than normal. In addition, the invisible path that leads to the top does not zig zag. The path from the first level to the second level is on the right, but the path from the second level to the third is also on the right. You will find the hole in the ceiling that leads to the hallway above on the left side of the room.
In this new hallway, you have a lot of breaking to do. First break a passage through the bricks to the right. When you reach the statues, jump up on top of the left statue head. Then begin breaking the two lowest levels of bricks along the upper passage. You must do this all the way to the left side. The first door that you uncover (O) contains a unique image of a man who provides information (he appears to simply restate everything that Viser's daughter stated when you rescued her from the previous stage, although this could be an error with the game's translation patch.) The real door of interest is the second one that you find (P) which contains the weapon shop which sells the Extra Sword for only 10 metal. Purchase it, and then break a hole up to the passage below the ceiling.
Start walking back to the right along this passage below the ceiling, and jump up as you approach the right side. You should be able to find the invisible gap in the ceiling that leads to the room above. All that you must do now is approach the right side of this room where you will be attacked by a large Golden Dragon. No attack will damage this dragon (although fortunately, attacking the dragon won't kill you either.) Instead, you must utilize a tool that was given to you by Viser's daughter; the Wizard's Soul. Activate the Wizard's Soul in your item screen, and press to use it and summon the wizard. He will cast a spell that will remove the defense of the Golden dragon, transforming it into a regular Silver Dragon which you are free to attack. Once you defeat it, the seal to the entrance (8) of the eighth labyrinth will be open. When you are ready, step inside.
The eighth and final labyrinth is rather large, and unlike many of the labyrinths you visited previously, you must explore a majority of this one in order to succeed. It features different music, and hosts the largest number of bosses, three, out of any labyrinth, and it even features Black Dragons in addition to Skulltas as regular enemies in certain rooms. You must visit the bosses in a particular order, or you will not be able to complete the game. Once you complete this labyrinth, the game is over, so you do not need to worry about getting out or continuing on to anywhere else.
From the start, climb down the ladder to the room below. Immediately, you will be introduced to the only new enemy of the labyrinth, the Gemon SS. Just as you might have feared, this enemies behave very much like Hyper Armors. They leap toward you when attacked, and they cannot be hit from the front. They are very difficult to fight and are best avoided rather than confronted. When you climb down, head immediately to the left.
In this room, you will notice a Skulltas on the lower level. You must climb down the ladder while doing your best to avoid getting attacked by the Skulltas. Exit through whichever door is easiest to pass through, as they both return you to the previous room. Then climb down the ladder to the floor below.
Although it is faster to walk to the right, you can proceed in either direction. Fighting the Metal Armors on this floor can be a good way to restore lost health. Continue walking until you find a ladder that extends to the lower level. Once there, take the door on the left, and climb down the next ladder to the floor below.
On this level will you have absolutely no choice, but to walk all the way to the left, climb down the ladder to the lower level. There you will face a Skulltas. Either fight him, or take a hit of damage and walk right through him to get past him. Then proceed to walk all the way to the right. You will face another Skulltas along the way. Ignore the first downward ladder that you reach, and take the one at the end of this floor (surrounded by two Gemon SS). This will lead you to the first boss.
The first boss is a regular Black Dragon. There is no special trick to him, so you can defeat him the normal way. Your reward for beating the Dragon is the King's Sword. It's not a weapon that you can use, but an item which will come in handy shortly. When you climb back up after beating the dragon, watch out for the Gemon that surround you, and walk to the left. Climb down the ladder here to the floor below.
Run away from the Gemon SS and go to the left. Continue all the way to the left until you pass through a one way door. Then, while carefully avoiding the enemies, climb down to the lower level and the floor below. Again, avoid the Gemon SS and head to the left. In the next room, you will face a free standing Black Dragon. You can very easily slip past it by running beneath it while it is in the middle of its huge leap. Return to the right. After one room, you will face yet another Black Dragon. Fight it or use the same trick to sneak past it. Continue right and you will pass through a one way door.
You are now directly over the room with the second labyrinth boss. Watch out for the enemies and climb down the ladder to encounter yet another woman enemy. This is in fact Princess Karin. If you attack her, you will of course die. To defeat her properly, you must access the item menu and activate the King's Sword which is now in your item box. Return to the game and press to use it. This will freeze the princess in place, allowing you to walk up to her and touch her, which will initiate a dialog. She will inform you that she is really Viser's daughter, and that you are the true Prince of Gulse, exchanged at birth 15 years ago. She will then give you the Holy Crystal, a necessary orb that grants you the power to damage the God of Darkness with your attacks.
When you are ready, climb back up. You will have no choice but to head to the right. Continue to do so, wrapping around to the first Black Dragon, until you get beyond him and reach a ladder that leads down to the floor below. Climb down that ladder. In the next room, you have no choice but to climb down. Carefully avoid the enemies and proceed to the floor below.
Once there, either jump over the Gemon SS in front of the right door, or attack it to cause it to jump over you. Then pass through the door, avoid the next Gemon SS that you encounter, and climb down to the lower level. Do not climb down the next ladder, or you will end up taking a one way warp back to the top of the labyrinth. (However, you might consider doing this intentionally if you are incredibly low on health, and wanted to fight Metal Armors in order to re-energize.)
Instead, continue to the left through the door to return to the lower level of the previous room. You are now one room above the final boss of the labyrinth. When you are ready, climb down the ladder to face… another Black Dragon. Don't be too disappointed though. Defeat this final dragon, and a dialog will begin with Ruva. He will inform you that he was behind the scheme to exchange you and Princess Karen, and he tricked the Gulse family and kingdom. He will then achieve the power he sought and transform into the God of Darkness.
Now you must defend yourself against a god. He tends to walk forward, spraying the room with three projectiles, much like a Skulltas or Dragon would do. When you hit him in the head with your sword or firebolt, he disappears, and teleports to some random location in the room. If he hits you, he will do tremendous damage to you, which is why it is good to have several yellow potions with you. Your safest bet is to remain against the left wall, where he is unlikely to teleport, and continue to hit him in the head whenever he appears, while avoiding the projectiles that he fires at you. Jump up to get your shots in while he is telelporting in an attempt to hit him in the head before he has a chance to attack. After you hit him enough times, he will be defeated, you will be immediately treated to the ending and the credits of the game. Congratulations.