Go back to the Tower of Spirits after obtaining the Bow of Light. Go up the spiral staircase, then step into the blue light at the top to reach floor 23. Go through the upper door, then go up past the arena and through the upper door.
Opening the Altar
Go up the stairs to reach the altar at the top of the tower. Use the stamp station here, then charge up the bow by holding the stylus on the screen for a moment while aiming the bow. Shoot the two eyes with a light arrow. Go down the stairs that appear, then go up and descend the stairs up above.
Go up to the top of the room and go down the stairs.
In this dark area, there are two Phantoms that you can access right now. Hit one in the back with your sword and have Zelda turn into a Phantom. Map out this upper left area of the room, then go back upstairs.
Have Zelda walk over the spikes to the right and step on the switch to permanently lower the spikes. Have Link walk to the right, then have Zelda go into the lava. Have Link jump onto Zelda's shield.
Have Zelda walk over to the right side of the room near the stairs that are blocked by the door, having Link get rid of the two fire keese in this area. Then have Link use the boomerang to hit the two crystal switches, having Zelda move him closer to the second one after hitting the first if necessary. Then have Link and Zelda go down the stairs in the upper-right corner.
Map out this area. There are no Phantoms in this upper-right area, but there are ghosts. Just step into the light of a torch to keep the ghosts away from you.
In the upper-left corner of this area, there is a sign that says "sometimes darkness opens a path." Go around and use the whirlwind to put out all of the torches.
After you do that, the door on the left side of the room will open. You can now access the Fire Phantom, so hit it in the back to switch Zelda into it.
Go to the lower left part of this floor, mapping the area along the way. As you get closer to the lower left, a Warp Phantom will appear to the left. Go near and create a distraction so it comes over to investigate, then hit it in the back. With Zelda in the Warp Phantom, hit the eye switch on the left side of the room with a light arrow. This will make a torch light up next to another eye switch elsewhere in the room.
For now, switch Zelda back to the Torch Phantom and use the upper-right stairs to go back up to level 30.
Go across the lava, then go to the top middle of the room and down the stairs.
Have Zelda walk to the left middle part of the room and use the fiery sword to light the two torches. This unlocks the doors to the downstairs. Go down the stairs.
Go up to the upper part of the room and have Link use the sand wand to create bridges over the sand for Zelda to walk on to reach the two torches at the top. Light them to reveal two treasure chests.
To reach the chests, have Zelda walk below the highest red platform and have Link jump onto her shield. Then use the sand wand to create a path for Zelda to carry Link to the two treasure chests. One of them is a random treasure and the other is a small key.
Go back the way you came to reach floor 29, then use the stairs on the right side of the room to go back up to floor 30. Go across the lava, then go down to floor 29.
Go over and switch Zelda into the Warp Phantom. Then go back up the stairs, across the lava, and down the stairs in the upper part of the room to reach the left side of floor 29.
If Zelda talks to the Phantoms here, they say that there is a weak spot in the wall on the upper left. Bomb the upper left wall and go through the crack. Make your way through the passages to get to the upper-left corner of floor 30.
There is a pile of blocks on the lower left. Just use a couple of bombs to get rid of them. Then, keep in mind that Zelda can't walk on sand and use the sand wand to get up on the sand, then jump onto Zelda's shield to go up to the switch and step on it. This reveals a Warp Phantom and some Phantom Eyes.
After doing this, have Link stand on the red circle tile at the bottom of the room. Then have Zelda target the Phantom Eye in the lower area, but don't take the stylus off of the screen. Wait for the Phantom Eye to be floating above the red circle.
When Link and Zelda switch places, it's okay to leave the Phantom Eye alone. Just run onto the sand and the Warp Phantom will sink and not be able to catch Link. Use the Phantom Eye to make the Warp Phantom show up, then have Link hit it in the back to switch Zelda into it.
Have Zelda walk across the spikes and onto the yellow triangle tile. Have Link walk to the left and step onto the yellow triangle tile to switch places with Zelda. Have Link go to the top of the room and use the bow of light on the eye switch. Then switch places with Zelda again so she can walk across the spikes to join Link.
Before going through the door that just opened, have Link get up on the sand up above to jump onto Zelda's shield. Together, walk to the left side of the room. Have Link use an arrow on the miniblin to stop it from bouncing around and attacking you. Then walk over to the pit on the left side of this area and have Link use the boomerang on the arrow shooter to make it point up. Shoot a light arrow into it, then go down the stairs that were revealed.
Switch Zelda into the Wrecker Phantom. Then have Link light the torch on the left side of the room using the boomerang to create a shortcut between the two areas. Shoot the eye switch on the back wall with a light arrow. Get the small key from the treasure chest that appears.
Before going back upstairs, blow out all of the torches to reveal a chest that contains a random treasure. Then go back upstairs.
Have Zelda roll into the blocks and statues to the left of the stairs. This will reveal a chest that contains the third small key.
Have Zelda roll to the middle of the room through the statues that are blocking the way. Go to the upper middle part of the room and go down the stairs.
Go down to the down staircase south of where the Torch Phantom is walking around. Go down these stairs to reach floor 28.
Unlock the three doors. Start by going down the easternmost door.
The camera will show you three eye switches. Have Zelda roll down, then left, then up through the boulder corridor. Have her hit the crystal switch to stop the boulders. Then have her roll back down the corridor, all the way to the bottom. Have her roll up the stairs and break through the blocks there. Then have Link go up and read the sign. It says to light them in this order: the undefended flame, the flame surrounded by sand, the flame surrounded by the abyss, and finally, the guarded flame.
Have Zelda roll up through the now empty boulder corridor. Then have her crash through the statues and blocks down below.
There isn't anything more that you can do on this floor yet, so go back up to floor 28.
Instead of going back down to floor 27, instead go up the stairs on the left side of the room to reach floor 29.
Switch Zelda into a different type of Phantom. Any type will do, as long as it is not a Wrecker.
Go back down to floor 28, then use the leftmost door to go to floor 27.
Make Zelda stay where she is and have Link run down to step on the switch on the sand, using the boomerang to get rid of the Phantom Eye. Then have Link get up onto the sand and then hop onto Zelda's shield. Have Zelda walk to the bottom of the room and have Link whip to the left side of the room.
Have Link step on the switch to make a permanent bridge appear. Have Link raise himself on the sand and switch Zelda into the Warp Phantom on the ledge. Then have her walk across a sand bridge to the blue arrow shooter on the platform to the left. Draw a line from Zelda to the arrow shooter to make her pick it up, then have Link walk up the narrow flight of stairs onto the column to the right. Have him shoot an arrow of light at the arrow shooter to activate the eye on the wall.
Then have Link drop down to the right side of the room and kill the Stalfos there. Have him stand on the red circle tile. Then have Zelda warp over to the rightmost Phantom Eye. Have her walk onto the red circle tile to the left.
After swapping places, have Zelda walk onto the switch up above, and have Link shoot an arrow of light at the blue arrow shooter.
Have Zelda warp to the rightmost Phantom Eye to join Link, then have the two of them go back upstairs together.
First, go back up to floor 29.
Switch Zelda into a Torch Phantom, then go back down to floor 28.
Use the center staircase to go to the part of floor 27 that you haven't gone to yet.
This is where you can solve the puzzle from the stone tablet that said to light the torches in a certain order: the undefended flame, the flame surrounded by sand, the flame surrounded by the abyss, and finally, the guarded flame.
Have Zelda hit the upper-left torch with her sword. That is the "undefended flame." Then use the boomerang to light the torch that is in the sand and the torch that has a hole surrounding it. Finally, Zelda must walk across the spikes to light the final torch. This will open the door that was blocking the way to the stairs in the upper middle part of the room. Have Zelda and Link go down those stairs.
You will be attacked by nine black chuchus. Have Zelda kill these one by one. Then a bunch of stalfos will attack. Use bombs to get rid of them easily. Finally, three Geozard Chiefs will appear. Have Link remove their shields with the whip. Be careful to hide behind Zelda to avoid the spewing flames. Team up with Zelda to quickly kill them with your swords.
Once the monsters are gone, the doors will open. Go downstairs with Zelda.
Phantoms of all four types will appear. First, take control of the Torch Phantom and light the two torches in front of the lower door to open it. A Phantom Eye will also appear.
Make the Phantom Eye see you while standing near a safe area. Run to the safe area after the Warp Phantom shows up, then run around and hit it in the back to switch Zelda into it.
Have Link stand on the sand to make the Phantom Eye see him and latch onto him in the area with the two switches. Since Zelda is occupying the Warp Phantom, it's not dangerous to let the Phantom Eye see you. When the eye is up there, have Zelda warp to it to be near the switches. Have Link walk up there and have him stand on a switch while Zelda stands on the other. This opens the doors behind the normal Phantom in the center.
Now switch Zelda into the Wrecker Phantom. Have her roll into the statues in the middle of the room above the Warp Phantom and normal Phantom, breaking all of the statues. Afterward, have Zelda roll into the two Phantoms to stun them so Link can run past and into the safe area. Then have Zelda and Link push the double doors open. Zelda must target one door and Link must tap the other.
Go through the door in the back to receive the Compass of Light. New tracks appear on the Forest Rail Map that lead into the Dark Realm. Walk into the blue glowing spot to return to your train.