Pit of Redemption

At the landing site of Merged Nothingness, there are two gates. One is locked and on isn't. Break down the unlocked gate and you will see a hole in the dark matter mountain. Go into the hole and you will be in the cave. After the welcome cinematic take the key on the ground in front of you and use it on the locked gate. Now head back to the hole in the mountain and go in. Have fun!!

Appearance (before the transformation)
At the entrance, you are on a small cliff overlooking the large chamber below. You will notice a spiral staircase made out of bones and a pillar with one hundred doors in the center. Head on to the staircase and a ghost will appear to warn you about the cave. Tell him you are strong and he'll tell you more about the cave. Go on the spiral staircase and choose to go down all the way. There is a Queen Candypop Bud, closed geyser, and an unusable portal at the bottom. Go back to the staircase and choose to go all the way up. At the top, there is another unusable portal and a small piece of crystal. Pick up the crystal and head back to the exit. The ghost will tell you about the crystal. Leave and put the crystal piece in the ship. It serves no purpose until a little later. Head back into the cave and at the spiral staircase choose to go the Pillar of Redemption. At the pillar, there is a small panel next to where you get off the transport. It shows you that only one door is open. Choose to go to that door and wait for the lift to power up. At the door, there is one final warning about the cave and the option to get back on the lift or enter the door. If you want to start your first Challenge Mode cave, go in. If you want to leave the cave ride the lift back to the platform with the panel. When there go up to the spiral staircase and choose to go to the entrance.

Appearance (after the transformation)
After you complete all of the caves on the pillar something happens. The pillar starts to spin rapidly until it blows a hole through the ceiling of the cave and goes through it. The inactive geyser at the bottom of the cave activates and moves to the center of the room. You can use it to head to the longest cave in the game with 100 floors, Mount Ordeals.