Upon killing the 10th Sslik Skeleton Reaver you'll receive the following message and a Broken Sigil Ring.
The last skeleton staggers backwards, but does not fall. It attempts to reach out to you, but is suddenly wracked by a violent spasm. With great effort, it removes a ring from its right hand and lunges forward to press the ring into your hand. It throws its head back, howling in agony, before shattering into thousands of tiny bone fragments. The ring is warm and heavy in your hand, but this might not be the best time for a detailed examination.
Return to Ssoren and examine the skeletons ring
Speak with Bastea in Kion about the ring the skeleton gave you.
Deliver 20 Maggot Hides to Bolo in Kion
Upon giving Bolo the Maggot Hides he will give you a Buffing Wheel
Return to Bastea with the Buffing Wheel, 36 Focused Viridian Azulyte, 10 Ground Garnet, and 20 Adobe Clay Chunks.
Bastea will give you the Repaired Sigil Ring, but when you wear it you have visions...