Talk to Huan Gui again. Choose the second option here, and she will ask you to check the illusion behind the Master.
After obtaining the Pipa, head to the Righteous Path Main Camp. If all goes well, your current exploration progress should be 98%. Let's go back now to complete it to 100%. Teleport to "Sunset Path" (you could actually have come here after getting the Golden Melon, but I forgot; this has been added in the previous section).
Once you reach the teleport point, turn around and go straight, entering through the small door we opened earlier (if the door isn't open, you'll need to circle around from the Banyan Tree Challenge on the right side of the save point).
After smashing the floor, obtain the Killing Intent Amber Fragment #4 below. Also, pick up the purple item nearby.
