The Illusory Pipa is a phantom edge capable of dispelling certain barriers, but also an important story item in Phantom Blade Zero, unsealing a special barrier in the north of the Meigu Lake area.
To craft it, you'll first need to arrive at the Order's underground tavern in Pangzhen, where you'll meet Myst, the third sister who's capable of repairing the instrument once you find its parts. Here's where to get each of them, though be aware they require significant progression through the game:
Illusory Pipa Head
Defeat the secret boss, Dusk, in the Village of Lu. Find Firefly's Memory Flowers as part of the Secrets at the Heart of the Lake quest to unlock the barrier at the Temple of Blue Fireflies, then drop down to fight him.
Illusory Pipa Strings
Defeat Yan Qiansui, The Zither Maiden at the sunken opera house in south Meigu Lake, accessible via north Pangzhen after you've defeated the region boss. Collect Yan'er's Memory Flowers floating around the island, with two towards Pangzhen docks, to access it and fight her.
Illusory Pipa Backplate
Defeat the final boss at the Mandate Encampment and collect it after. You'll need a key found in Pangzhen (details in linked guide) to access this region near the entrance to the Village of Lu. Once inside, fight through the region to the final boss and grab the backplate on a table just after the battle.
Once you've got all three parts, head back to Myst in Pangzhen and select the relevant dialogue option to repair the Illusory Pipa. Now you can unseal the barrier in the northeast of Meigu Lake.
