After you remove the seal in the Cryptic Cavern, you can reach the Gerudo Sanctum.
Find a Waypoint
When you enter the Gerudo Sanctum, there will be a cutscene. Go north through the door.
Go to the right and climb up the rock wall, avoiding the wind from the Wind Cannons. Whenever you have to go across the gap between the two rock walls, go as high up as you can without touching the wind, and you can just move left or right to fall off of the current rock wall, then start pressing up to climb up the next rock wall.
Go to the left and bind to the boulder, and push it to the left until you can drop it in front of the Wind Cannon. Then jump to the ladder on the left, and climb up the ladders.
Check on the waypoint to add it to your map.
Get a Small Key
If you go through the door on the left, the door will lock behind you. Dodge the flying tiles in this room. When they are all gone, open the chest to get 20 rupees.
Then go back through the east door, and go through the next door. There is a bar that is moving slowly upward into the wall, which makes the two stones in front of the door slowly slide closed. You can go up to the handle and press A to hold it, then walk south to pull the bar downward, reopening the stones. However, with the conveyor belt pushing you back, you won't be able to reach the door before the stones slide closed again.
First, create a monster echo to defeat the two Keese. Then create four Old Beds on the top row of the conveyor belt. The leftmost bed will fall off, and the beds to the right of it will stop when they hit the leftmost bed. Then walk across the beds and press X to bind to the bar in the wall. Walk back across the beds, and when you can't walk farther, press ZR to release the bind, then jump up to the ledge and go through the door.
There is a door in the north wall with two handles on it. Bind to one of the handles and pull down on it to rotate the door. Go north through the opening. It doesn't matter which side you go through.
Open the chest to get a Small Key.
Learn a New Echo
You can warp to the waypoint next to the locked door, or just go there on foot. Check on the locked door to open it. Go through.
Check on one of the statues and learn the Snake Statue echo. Then go through the north door.
Find a Second Waypoint
You will have to battle two moth-like monsters. Boomerang Boarblins work well against them. Defeat one and you can learn the Mothula echo. After you defeat both, the locked doors open. Go through the west door, then go through the south door.
You can use Flying Tiles to get rid of the wooden boxes on the left. Then carefully go across the conveyor belt to reach the left side of the room. Go down the ladder.
Go partway down the ladder, then create a Caromadillo Lv. 2 beneath you so it starts attacking the other one. When the enemy Caromadillo is gone, go to the left and create a Holmill on the sand. Go down the hole and stand in front of the chest, and open it to get a Golden Egg.
Create a Holmill on the sand in the floor and wait for the Caromadillo to be temporarily stunned, then go down the hole and climb partway up the ladder on the right. Create a Caromadillo beneath you to fight the enemy Caromadillo. When the enemy Caromadillo is gone, go to the left and go down the ladder.
Check on the waypoint to add it to your map.
Get the First Clue
The sign in this room says to look for clues on this floor to find out what you need to put on the two pedestals.
First, bind to one of the handles on the east door, and move west to rotate the door. Go through. Defeat the Holmill using Crawltulas or other fast monsters, or just use swordfighter form. Then create a Wind Cannon to blow away the sand. One of the eastern sand piles has an Aruroda hiding under it, so defeat it before you get rid of more sand. A southeast sand pile hides a treasure chest that you can pull up by binding to it and moving away from it. The chest contains 10 portions of rock salt. The northeast sand pile hides one of the clues. The clue might be random for your game. For example: . Make a note of the clue before you continue (or you can just warp back here if you forget).
Get the Dungeon Map
Then go west to the previous room, and go through the west door. You'll be locked in the room and have to defeat the ghost-like monster there. It can create a flames on the ground, and it can teleport to a different location in the room. It moves very quickly and tends to move backward away from enemies. Mothula works well against it. After it is defeated, you can learn the Poe echo. Open the chest to get the Dungeon Map.
Find a Third Waypoint
Go through the door in the southwest part of the room, and you will be outside in the Still World. There will be a cutscene. Go south, then follow the path. Defeat or ignore the monsters, then bind to the buried treasure chest and pull on it to lift it out of the sand. Open it to get 20 rupees.
Continue making your way along the path, and you find a ladder. You can bind to a handle on the cylinder beneath the hammer, and pull the handle to rotate the cylinder clockwise so you can reach the bottom part of the ladder. Climb up. Open the chest on top to get 50 rupees.
Go west, then north, then east, then south to an island with quicksand on it. Use a trampoline or other echoes to go to the upper ledge, then go south to the large building. Check on the waypoint.
Learn a Second New Echo
Defeat the monsters here, then use a Wind Cannon to blow away the sand piles. The easternmost sand pile hides a dark Aruroda, and the southernmost pile hides a treasure chest. Open it to get a Monster Stone.
Go to the eastern part of this island and go down the two rock walls. Before you go through the door here, go east and create a trampoline with a Platboom next to it, and ride it up to the higher part of the island.
Go northwest and create a ReDead to defeat the dark ReDeads. They're immune to each other's screams. After the dark ReDeads are gone, go north to the cylinder, bind to the handle on the left, and pull the cylinder counterclockwise. Go up the ladder and check on the statue to learn the Hawk Statue echo.
Learn a Third New Echo
Then warp back to the waypoint in the middle of this area, and go southeast to the door that you haven't gone through.
The sunken area is made of quicksand. Defeat the Sand Piranha, then pull the bar south until it won't go further. Go around to the south part of the floor, release the bind on the bar, and make a Flying Tile pointing north. Before it hits the north ledge, jump north so you don't fall in the quicksand when the tile hits the north ledge. Then go through the north door.
There are two Gibdos and a ReDead in this room. Use an Ignizol to burn the Gibdos. Use a ReDead to defeat the other ReDead. Then go up to a statue and learn the Cat Statue echo.
Find a Fourth Waypoint
The sand piles don't have anything under them, so just bind to the northern statue and move it to the side, then go through the north door.
Check on the waypoint to add it to your map. Then go west, and through the north door. There will be a cutscene.
Dark Archer
You will fight the swordsman from before, but this time, he uses a bow and arrow. Use swordfighter form, or Club Boarblin Lv. 2.
After you defeat him, three more of them appear. Each one can charge up and shoot three arrows at a time.
After you defeat those three, there will be a cutscene. After that, check on the bow to receive the Bow of Might. When you're in swordfighter form, you can now press X to shoot arrows.
Find a Fifth Waypoint
You can use a Wind Cannon to get hearts and energy from the piles of sand. When you're ready, go through the north door.
Energy will keep appearing in this area, so you can freely use Swordfighter form here. Go to the right and switch to Swordfighter form, and shoot an arrow at the Beetle Mound to destroy it. Then go to the lower level, get rid of any Beetles that are still there, and in Swordfighter form, shoot arrows at the dark membrane across the gap to destroy it. Use a Flying Tile or other echoes to go across to the right side. Go up the ladder, and you can optionally go to the left and switch to Swordfighter form and hit the dark membrane to get rid of it. Then go to the right and climb up the ladder.
Check on the nearby waypoint to add it to your map.
Learn a Fourth New Echo
There are flamethrowers blocking the path across the conveyor belt, but each flamethrower has a handle on its back. Face the back of the nearest turret and press X to try to bind to it. When you have it, pull it to rotate it counterclockwise. Then bind to the handle again and turn it counterclockwise so it's pointing north. Then you can reach the southeast corner.
Bind to the back of the nearest flamethrower to the north and pull on it to rotate it so it faces north. Then bind to the next flamethrower and rotate it counterclockwise until it points west.
Then go up to a shimmering statue and learn the Elephant Statue echo.
Get a Second Small Key
Go west and open the chest to get a Small Key.
Get the Second Clue
Warp to the waypoint in the southeast part of the Sanctum. From there, you can go south twice to find a locked door to the east. Unlock it and go through.
Go to the middle of the north wall and press X to bind to it. There are handles on the left and right side of the middle part of the north wall. Pull downward to rotate the door. Go through either side.
First, stand south of the southwest corner of the hole in the floor. Face north and send a flying tile north to hit the wooden box, or just shoot it with an arrow. This will make the Wind Cannon go lower down. Then go to the right side and bind to the flamethrower. Move upward to rotate it counterclockwise, then rotate it clockwise twice. This should light the southern and northwestern torches. Then go to the southwest corner of the room and try to bind to the flamethrower from that direction. Move west to rotate the flamethrower clockwise, lighting the final torch. Go to the northwest corner and read the sign. The clue might be random depending on your game. Here is an example: . Make a note of the clue if needed (but you can teleport back to the room with the clue if you forget).
Solve the Riddle
You should now have both clues. Each clue will refer to one of the four statue echoes that you learned here: Cat, Elephant, Snake, or Hawk. In the + Pause menu, you can check your notebook to read the descriptions of each statue to figure out which statues the clues are refering to.
Warp to the southwest waypoint and you should be in the room with the riddle. Put a different statue on each of the bright tiles on the floor. Make sure that each statue matches one of the descriptions in the two clues that you found. You can put them on the tiles in any order.
If you put the correct statues on the tiles, the north door will open. Go through.
Remove Some Sand
Bind to the handle in the seal in the east wall and pull it west. Watch the cutscene. Then go east through the opening that you pulled the seal out of.
Reach the Big Chest
Bind to one of the handles in the side of the ring and rotate the ring until it sinks downward. Then go to the round object in the southwest corner of the room and press A to grab it, then move upward to rotate the inner ring. When the inner ring sinks downward, you can open the Big Chest to get the Big Key.
Go up the stairs in the northeast part of the room. Then go west and check on the waypoint to add it to your map.
Then unlock the Big Door and go through. After a cutscene, you battle Mogryph.