Trap the Soul (enchantment)

Trap the Soul
...

Trap the Soul Guard
This item stores an overwhelming, merciless power deep within. When the wearer of this item is successfully attacked in melee, this power occasionally comes to the surface, sucking out the life force of an enemy and imprisoning the essence of their body and soul in a gem.
 * Appears to work once after each rest as per the Trap the Soul spell 20HD version