After you deliver the Sacred Water to Faron, you gain access to the Ancient Cistern.
Get a Small Key
Use the Bird Statue nearby if you wish. Then jump across to the locked door. The nearby sign tells you where to look for the symbols carved into the statue, to find out the secret order of the temple. "First the back, then the rear, then the back of the right hand, and finally the back of the left hand."
If you go around the room to look at these places, you find that the sacred order is up, down, left, right. You can get the silver rupees in the hands by doing a spin attack as you get close to the rupee. The hand will permanently close, making it easier to see the hidden symbols.
Go to the east side of the room and pull the red bar down. Go through the door.
Hop down onto the lily pads. The one that you land on will flip over. Climb up onto solid ground. Go north and you will see some Skulltulas. Flip them over by swinging your sword upward, then kill them with a fatal blow.
Go north and you will find a sign that mentions the sacred order of the temple. Hit the top crystal, the bottom crystal, the left crystal, and the right crystal. The door will open. Go through.
There is a red rupee underwater in the southwest, and an underwater passage in the east wall that are blocked with lily pads. Go across the lily pads, killing the two Skulltulas that come down by swinging the sword sideways, then using a forward thrust when the purple belly is facing you. If you want the red rupee, climb up the ivy in the southwest and hop down to the lily pad that is blocking the path to the rupee. Then, to continue on, climb onto the platform on the southeast side and then jump down onto the lily pad that is blocking the eastern underwater passage. Swim through the passage, using spin attacks to break through the wooden fences. Climb the vines at the end and go through the door.
Open the chest to receive a key.
Fight the Stalmaster
Drop down below, and step on the water spout to go to the upper level. Kill the Deku Baba and go past where it was, and drop down from the ledge to find a door. Go through the door to return to the main room.
Use the key in the locked door in the center. After a brief cutscene, drop down to the lower level and use the Sailcloth to land safely. A Stalmaster will attack. In the first phase of the battle, it will be possible to hit with horizontal, vertical, or diagonal slashes. After you hit the Stalmaster a few times, it will use weapons in all four arms, and when it moves its arms there will only be one direction that works, either from the left, from the right, from the top, from the bottom, or a thrust. Pay attention to the sword positions. You can do a backflip or run away if the Stalmaster is about to attack, or you can try to do a Shield Bash to deflect the attack, which will knock off its arms temporarily, allowing you to hit it many times.
Get the Whip
After you defeat the Stalmaster, go through the door and open the chest to receive the Whip. Go back to the previous room and use the whip on the water faucet switch near the wall, by hitting it with the whip to latch onto it, then whipping sideways to rotate it. Use the water spout to go up, and if you wish, you can turn on the next water spout, and the next one, to reach the top, where there is a sign that says "Look for the key that lies beneath the earth."
Get the Dungeon Map
Exit through the door on the third or second floor. Both lead to the same area.
Go to the east side of the room and use the whip on the bars on the wall to swing over to a blue chest beyond the grass that contains the Dungeon Map.
Get the Blessed Idol
Go to the west side of the room, where there is a waterfall. Use the whip on the lily pad that is upside down near here. Catch it with the whip, then swing the whip up or down to flip it over. Then jump onto the lily pad that you flipped. Use the whip on the red bar on the wall and swing it down. This will stop the waterfall. Swim into the fish mouth that the waterfall was blocking.
After you swim through the passageway, you emerge from a large fish mouth. Go around the back of the fish to find a chest that contains a red rupee. Then go toward the exit. Kill the Skulltula by swinging the sword upward to flip it over, then do a fatal blow. Use the whip through the bars to pull down the red bar switch and open the bars. Go through.
There are butterflies near a wall here. Face the wall and strum the harp to reveal the Goddess Wall. (You might want to kill the Bokoblin Archer first.)
After you kill the Bokoblin Archer, use the whip on the bar on the wall near where it was, to swing to the ivy across from it. Climb up, kill the Deku Babas, and run up the rotating vine wall to grab the vines. Climb upward so you can stop on the ledge on the west side of the room to recover your stamina. Then climb back up onto the vines, and climb down onto the southwest ledge. Kill the Bokoblin Archer, then use the Beetle to kill the Walltula on the vines across the way. Before you swing across to those vines, climb down the vines on this ledge to reach the area below the red bar and the vines where the Walltula was. Use the whip on the red bar on the wall east of where you are standing (stand back far enough so you can target it), then turn around and climb the vines. Use the whip to swing across to the vines next to the red bar. Climb up and kill the Deku Babas, then use the whip on the water switch. Jump into the whirlpool.
Save at the Bird Statue, then use the Beetle to cut down the Skulltulas. They will flip over the lily pads and drown. When the lily pad against the east wall is flipped upside-down, it uncovers an underwater passage. Swim through it.
Go to the surface. Use the whip on the Bokoblin to steal its key. It will start shooting arrows at you. Unlock the door and go through. There will be a brief cutscene. kill the Bokoblin Archer. Then go east and enter the pipe that the water is going into.
Up above, go to the ledge with the bars, and save at the Bird Statue. Then do a spin jump to reach the ledge on the east side of the room. Use the whip to flip the lily pad that is below the vines, then kill the Walltula with the whip. Run up to the vines and climb up. Go to the top level and kill the Quadro Baba. Then jump down onto the lily pad in the water below to flip it over. Swim into the passage that the lily pad was blocking, and swim downward to get the red rupee, then go through the passage, using Spin Attacks to kill the Froaks.
Go up the stairs and kill the Deku Baba. Then use the whip on the water switch to raise the lily pad up that you flipped earlier. Go east and climb back up the vines so you can reach the floating lily pad. Use the whip to flip it over, then jump across it. Follow the path and you will reach some bars. Use the whip on the red bar to open the way.
There is a Furnix flying around up here. Wait for it to reveal its tail, then whip its tail and use it to pull the bird close to you, then do a fatal blow.
Look to the side to see some vines on the wall. Climb down and land on the small, cracked platform, and use the Beetle to kill the Walltulas. Climb to the small chest to get 20 rupees. Then climb to the ledge to the south, letting go of the vines when there is a gap below you so you can move upward to grab the ivy beneath the gap. When you reach the ledge to the south, activate the water switch to create a water spout, giving you a shortcut back to here. Then go south and use the whip on the lever. You will see the giant statue in the center be lowered to the bottom, where the big chest is.
Save at the Bird Statue to the south, then go through the door in the big statue. Use the Sailcloth to float down to the lower level, and go through the door.
In this creepy place, you will encounter Cursed Bokoblins. To kill them, hit them until they fall over, then do a fatal blow. You can whip and pull them to stun them temporarily, and if you have the Sacred Shield, you can do a Shield Bash toward them to stun them.
If you touch the purple water here, you will be temporarily cursed, and won't be able to use items until the effect wears off.
There are some rupees and hearts in the glowing blue eyes of the large stone face across from the door to the statue.
Go east around the back of the statue, and follow the path. Kill the Fire Keese, then read the sign up ahead. "A gemstone shines deep within the eye. Strike it to shut the mouth and dam the flow."
You can face the wall and strum the harp to reveal another Goddess Wall here.
Go to the lily pads in the purple water, turn to face the waterfall, and send the Beetle into a glowing blue eye to hit the pink switch within. Then go back to the area behind where the waterfall was, and use the Beetle to pick up a bomb. After the Beetle goes through the arch, turn it to the right, and make it drop the bomb on the large cracked stone.
Go to the lily pads and use the whip to flip over the one that is upside down. Jump across the lily pads and go northeast. Use the whip to swing to the platform where you dropped a bomb on the cracked stone. Jump onto the rotating vines and climb up to the top. Jump onto the next rotating vine wall. Don't go to the platform where you can see a wheel spinning very quickly down below. Instead, keep riding the vine wall to go to the southern platform.
Follow the path to some vines on the wall. Jump to them and climb up. You will be near some bars. Use the whip to switch the lever, changing the direction of the spinning wheel. There are no spikes on the other side, so just jump down onto the spinning wheel and get off on the ledge on the other side.
Kill the cursed Bokoblins and go up the slope. Jump onto the rotating vine wall. You can keep holding onto it, and you will reach the wall and drop to the southeast ledge. Go along the ledge and jump across to the vines. Use the whip to change the direction of the spinning wheel again. This causes the rotating vine wall to change direction as well. Go to the rotating vine wall and climb up. You can once again keep holding onto it, and as before, you will reach the wall and drop to the southern ledge.
Kill the Fire Keese up ahead, then drop down. Don't go to the center of the room yet. Instead, use the whip on the water switch on the side to give yourself a shortcut back to here with the water spout.
Now go to the center of the bright spot and grab the rope in the center. A bunch of cursed Bokoblins will come out and start climbing up to you. Climb up and keep climbing. If a Bokoblin grabs you, follow the on-screen instructions to shake it off. Or you can try sliding down the rope partway to try to knock the Bokoblin off. Keep climbing until you return to the upper level.
Up above, the sign says "Return the stone giant to its original form, and descend below the earth again along the thread. There you will find the key to the path ahead."
Use the nearby Bird Statue to save. Run up the wall to pull down the red bar, or just whip it. This will extend a ledge. Use the whip on the lever to move the statue back to its original position. Then climb back down the thread to the underground area. There won't be cursed Bokoblins this time. If you didn't activate the nearby water switch earlier to create a shortcut, you can do so now. Jump down next to the water spout, then go northeast and open the chest to receive the Blessed Idol.
Reach the Boss
As you might have guessed, a bunch of cursed Bokoblins will appear around you after you open the chest. Just run past them and out of the pit. The giant statue will automatically descend, crushing them.
Go into the giant statue and ride the water spouts all the way to the top. Use the Blessed Idol in the lock to open the top of the statue. Activate the four water switches on the top to make the statue rise into a room up above. Save the game and go up the stairs.
The following battle can confusing because you have to repeat the steps so many times that it might seem like you are using the wrong strategy. However, if you do what is described below, you will succeed.
One of the tricky parts of the battle is making sure that you aren't targeting the wrong thing. Try not to be hasty.
If you are close enough, Koloktos will swing an arm downward. Get out of the way before it hits you with its arm, then go around the side of the arm and use the whip on the red orb to pull the arm off. When it exposes the red spot on its chest, attack its chest repeatedly with the sword. Slashes are effective; no need to use forward thrusts. If you wait too long, Koloktos will swing its arms at you before you can hit the red spot.
Koloktos will sometimes throw axe blades toward you. Just keep your distance and hide behind columns to avoid this. The axes go around like boomerangs back to Koloktos unless they hit you or a wall or the ground. The axe blade might go back toward Koloktos and then go back toward you again, so be careful.
Repeat the above strategy. Eventually, Koloktos will start walking around while holding many swords. It might shine a purple light and summon cursed Bokoblins at this point. These can be killed by hitting them repeatedly, with no need to do a fatal blow.
Let Koloktos swing the swords and get them stuck, then use the whip to pull off the arms. Pick up a sword right away. You can cut off the other three arms with this giant sword, or you can just swing the giant sword sideways near Koloktos's legs to cut the legs off. Then run around to the front and swing the giant sword to cut open the cage on Koloktos's chest, then hit the red spot repeatedly.
If you cut off all of the arms, Koloktos will run toward you. Get out of the way to let it hit the wall and get stunned, then swing the giant sword sideways at the legs to remove them. Go around to the front and swing the giant sword to break the cage, then hit the red spot over and over.
After you do this, Koloktos will reassemble itself and swing its swords wildly, so run out of the way as soon as possible and wait for it to stop swinging the swords before approaching it and repeating the above process. Repeat the strategy until Koloktos dies.
Get Farore's Sacred Flame
Get the Heart Container, then go through the glowing door and use a Skyward Strike on the crest. Your sword will now do twice as much damage as before.
Fi says to return to the Isle of Songs.