After getting the Mystic Statue from the Viper of the Sky Garden above Nazca Desert, you arrive in the underwater palace of Mu.
Seaside Palace
You arrive in the Seaside Palace. Go east and hit the skeleton. It freezes. There is a door to the Dark Space to the east. Keep going east and you find Kara looking ghostly. Open the chest to get Red Jewel #20.
Go west again, then down the stairs. From there, go west and then use the leftmost door. Go west and you find Erik, also looking like a ghost. Go all the way to the east to find a chest. It contains Red Jewel #21. Then go west and use the stairs again.
Go into the door to the right of where you came out. A voice tells you that the fountain is in the basement, and you can find the stone there. Go all the way to the east to find Lilly. She joins you. Go west to exit the small room. There is a door near the room where you found Lilly. Go into it. Use the next set of stairs and a voice will mention the Purification Stone. Go west and use the stairs there.
Go east and kill the blue Slipper. Keep going east, then use the door all the way on the right side of the room. You find some coffins. Check on one of the closed coffins and Lilly will open it for you. Check on the coffin on the left to get the Purification Stone. Go back downstairs and then go into the door to the left.
In this room, Skuddits will fall from the ceiling. From here, go as far west as you can, and go into the door all the way on the left. Open the chest to get Red Jewel #22. Go back downstairs and go east, then go into the first door you pass. Go west and you find Neil and Lance. Go east and use the door at the east end of the room.
You reach a scary-looking fountain. Equip the Purification Stone, then stand at the top of the fountain and use the stone. After the water turns blue, go upstairs. Go west and you find a person. You learn that the demons you encountered earlier were actually humans who had been turned into demons. Go west past the blue-haired woman and go into the door to go upstairs. Go east and into the door, then go west up the long staircase and go into the door at the end.
Go east and into the door near the blue-haired woman, then go into the stairs near the purple-cloaked man. Go west and you find another blue-haired woman. Go down the stairs in the middle of this area, then go west to find a man who gives you the Seaside Palace Key. Go east and go through the door, then go west and use the door there. From there, go east, down a short flight of stairs, past a purple-cloaked man, then use the door. Go west and use the Dark Space door to save the game. Then go west and equip the Palace Key to use it on the grey door. Then go west and use the door in the south wall.
Mu
Go east and kill the Slippers. Then go south and kill the Cyclops. Continue south, killing Slippers and Cyclopses until you clear the path to the east. Go east. Kill the three Slippers and go north. Go north and kill the Cyclopses. At the top of the path, go east to the next area.
Go east and kill the Flasher, hitting it whenever it appears. Go east and kill the Cyclops in front of the chest. However, the chest is empty. Go northeast and kill the Slippers. There is a strange bubble, but you can ignore that for now. Go east and kill the Flasher.
Go southeast and kill the two Cyclopses. In the narrow passage to the south, there is one of those bubbles. Hold L or R to pull the bubble up out of the passage. Go south past where the bubble was. Kill the Skuddits, then go southwest and kill the two Cyclopses. Go west and kill the Slipper, then go west and then go south to go to the next area.
Go east, avoiding the floor spikes by waiting for them to retract before you walk across. Go east and kill the Slipper. There is a door to the east, but there is nothing that you can do in the Room of Hope yet. Go east and kill the Flasher. Then go south and hold L or R to pull the bubble toward you. Go south down the passage that the bubble was blocking.
Keep going south and kill the two Cyclopses. Then go west from there and kill the Slippers. Go north and kill the Cyclops and Flasher, then go east and kill the Skuddits. Then go southwest to reach a treasure chest, but it is also empty. Go west to the next area.
It appears that there is nothing here, but if you go back to the east, Lilly mentions that the empty chests are all in locations where the two statues' line of vision crosses. Go back to the west and stand on the spot that the two statues are both looking at, then check that spot to find a Statue of Hope. Go back to the Room of Hope and put the statue on the pedestal there. Four cloaked figures mention the Sun God Rama and the power of the ocean.
Outside, the water level has changed. Go east, then south, then go down a ramp to the lower level. Follow the path west and kill the four Slippers at the end. Then go back the way you came. Go west past the Room of Hope and use the exit to go back to the previous area.
Follow the path north until you reach a ramp to the lower area. Go down it. There is a Flasher that will appear near the ramp. Move around to make it show itself, then kill it. Go west from the ramp, staying in the lower area. You will find a Cyclops blocking the path. Kill it, then go south and then west. You will find a row of sharp spikes rising from the ground. Double tap the directional pad to run left past the spikes. Just west of the spikes, go north to find three Slippers. Kill them, then go south and then west to find a Dark Space. You can transform into Freedan here.
Leave the Dark Space and go east, following the path. When you reach the ramp, go south from the ramp. Along the path you will find a flashing worm of energy. It can't be harmed, so just make your way past it, and follow the path until you reach the entrance to the next area.
Go east and kill the Cyclops, then continue east and kill the Slipper. Go south. There is another slipper, as well as a bubble. There is also a blue slope that you can't walk up. However, if you move the bubble until it is south of the blue ramp, you can bounce off of the bubble to go up the ramp. Just hold L or R to drag the bubble toward you. Kill the Cyclops at the top of the blue ramp, then go west. You will encounter a Flasher. Kill it, then go west to reach the next area.
Go west and kill the Slippers. Go north and kill the Slipper, then go south and then southwest to reach the exit to the next area.
Follow the winding path. You will see two switches. They both lower the spikes at the end of the path for a short time. Before hitting the switch, go up and kill the Slipper. Then go back down and hit the switch, then quickly run north and then south to go past the spikes before they rise. Remember to double tap the direction button in order to run. Go to the next area.
Follow the path and kill the Flasher that appears. Go south and continue to the next area.
Kill the Slippers along the way and then carefully run past the energy worms in the narrow path to the west. From there, go north to the next area.
Kill the Slipper that you encounter, then continue along the path to reach a Dark Space. Transform into Will to receive the Psycho Slider ability. This allows you to go through narrow cracks. To use it, double-tap a direction to run, then press the attack button while running.
Leave the Dark Space, then go back the way you came until you find a hole in the green wall. Use Psycho Slider to go through. Go east and follow the path all the way to the end, where you find a bubble. Drag the bubble toward you by holding L or R. Move the bubble so that it is just south of the blue ramp. Use the bubble to bounce up the blue ramp. Go west, then north. Kill the Skuddits and Cyclops. Then go east and kill the Slippers. Go east, then south, and kill the four Cyclops while avoiding the energy worm. Continue going south, then go west when the path splits and kill the Skuddits. This reveals a statue.
Go east, then south. Go west past the spikes, killing the Slippers. Go all the way west and kill the Cyclops. Another statue is revealed. Go north and kill the final Slipper to increase your STR. Go south again, then east. Check on the barnacle that is to the left of the western set of spikes. This is where the two statues are looking. If you check on the correct barnacle, you will find another Statue of Hope.
Now go back the way you came, going down the blue ramp and sliding through the hole to the northwest. From the southern end of the hole, you can go southeast if you want to go back to the Dark Space to heal up. Otherwise, go west from the hole to reach the next area.
Hit the switch to lower the spikes, then go north past them. Make your way north to reach the next area, then go north from here, going all the way north up a ramp, then go east to find another hole in the wall. Use Psycho Slider to slide through.
Go west, then north to find a ramp. Go down it, then go northeast to find another Room of Hope. Inside, use the Statue of Hope on the pedestal. The four cloaked figures appear again. Go outside. The water level has gone farther down. Go south from the Room of Hope and go down the ramp to find Red Jewel #23. Go back up the ramp from the treasure chest, then go up the ramp to the left. If you go west, you can return to the Seaside Palace and heal up in the Dark Space. Otherwise, go to the top of the upper ramp that led to the second Room of Hope, then go south along the dark grey path until you reach the crack in the wall. Slide through.
Go west and down the ramp. Then go east and go down the ramp while avoiding the energy worm. From there, go south and east to reach the next area. Two Flashers will attack in the next area. Kill them to increase your DEF. Then go north to the next area and kill the Flasher that attacks. Go east from there, killing the Slider on the way, then go northeast and kill the two Cyclops. Your STR will increase. Open the treasure chest to get Rama's Statue.
Go back the way you came. When you return to the area with a ramp to the upper level, go west instead. You will find a crack in the wall. Slide through. Two Flashers will attack, and there are some Slippers in this area as well. Kill them all to increase your HP. There is a Dark Space to the west if you want to save the game. Otherwise go north to the next area.
A Flasher will attack. Go northeast and kill the Slippers, then go up the ramp at the top, killing the Cyclops there. Go east and kill the Cyclops and Slipper. Your HP will increase. Open the treasure chest to get another Rama Statue. Go west and down the ramp, then go south to return to the previous area.
You can transform back into Freedan if you wish. To do so, you have to go east through the crack in the wall, then north up the two ramps, then north through the crack in the wall, then north and east to the next area, then east to a ramp, then down that ramp and west to reach a Dark Space where you can transform into Freedan. After that, go east past the ramp and go a long way around to the other Dark Space, then down the ramp from there.
Keep going south to go to another area. Kill the two Flashers that attack. Your DEF will increase. Go south again, then east to reach the next area. From there, go northeast to arrive at the Sanctuary. Equip the two Rama Statues and put one on each of the two pedestals.
In the next area, go to the top of the room and check on the one statue that is different. The spirit of Rama speaks to you, then wandering spirits appear around the room. Talk to each spirit, going downward through the room. After you talk to the final spirit, go back and talk to Rama. You get the Mystic Statue and Rama opens the path for you. You can go south to return to the Dark Space and save the game. Then go into the door behind Rama and follow the path. Two vampires are holding Erik hostage.
Jack and Silvana
Each vampire can send fireballs down the paths next to it. Jack's fireballs move more quickly, so you may wish to defeat him first. To avoid the fireballs, don't stand at a crossroads or on the same line as a vampire.
The the vampires can surround themselves with spinning energy balls and float around the room toward you. In addition, if the two of them float near each other, they might raise their capes and send a large energy ball at you. Avoid the energy ball at all costs. It causes a huge amount of damage.
Don't stay close to the vampires for very long. Just attack once or twice, then run out of range of their attacks. Don't let the countdown make you panic. You have plenty of time. The hardest part of the battle is getting away from the vampires and avoiding the huge energy ball. You should follow the vampires, but stay at a distance to avoid their spinning energy barriers, then rush in when you have a clear shot.
After both vampires are gone, you transform back into Will if you aren't Will already. Check on the bomb from behind in order to defuse it. Choose whichever wire you want. Afterward, go south to the bottom of the screen. You and the others will go through the underwater tunnel. Talk to everyone, then go east and check on the mushroom, then go back to your friends. After some cutscenes, you arrive in the Angel Village.