The Magical Stone: Nier Replicant Guide
You can pick the quest from a Fortune Teller in Forest of Myth (after acquiring all key fragments). The woman is sitting near the first house on the right. She needs your help in obtaining a gazing stone.
Now, speak with Popola in the library to know the location of the gazing stone. She will tell you that the stone location is on top of the Lost Shrine. Take the boat to Lost Shrine.
Climb up to the roof using the wooden ramp and reach the area with all the broken walls. You can use the push block on the right to get on top of the shrine. Continue going to the north side of the rooftop, and you’ll reach an area where a boss shade spawns. Defeat it, and you will obtain an ‘Eye of Power’.
Now, head back to Forest of Myth and give the stone to the woman. Here you can accept her offers for a free reading. You will be transported to a familiar location similar to the building at starting of the game. Go inside the building, there is a box you can break where you will find the “Iron Pipe” weapon. Defeat all the shades to return from the dream and complete the quest.