Grief Seeds are the remnants of a Witch or Yoma's essence when they are defeated, and are effectively a small piece of the Witch or Yoma that has gone into stasis. Wishborn are able to use these small black gems to cleanse their own Soul Gems to ward off corruption, as a Grief Seed will "absorb" a certain amount of corruption before its energy is exhausted. The amount of corruption withdrawn depends on the strength of the Witch or Yoma whose essence it was derived from, with more powerful beings offering more corruption cleansing upon their demise. It is recommended that Grief Seeds are returned to Kyuubey for disposal once they are exhausted, as a Grief Seed is capable of rebirth after a certain period of time if the it is left idle, even after it has been used to cleanse a Soul Gem's corruption.
A Grief Seed is what is left of a Soul Gem that has been corrupted beyond the ability to be cleansed; it represents the grief and despair in a Wishborn's soul, with hopelessness having overcome all other rational feelings within.
Currently, there are Three known Grief Seeds that are in the possession of locals in or around the Cleft of Dimensions. Acquired Grief Seeds should be used and disposed of, as mentioned above, as soon as possible, else they will spawn a special kind of Witch that may or may not be considered more dangerous than standard Witches. This is a rare occurrence, as most Wishborn are not irresponsible enough to let this happen. Also of note, Grief Seeds' incubation and reawakening process is severely exacerbated when carried or possessed by those who are not Wishborn.
Current Grief Seed Retainers and Their Locations:
Tyrranis (Truce) - Racharge Level: 88% - Rebirth Status: Looming
Johnathan (Wutai) - Recharge Level: 19% - Rebirth Status: Danger
Mollianne (Viorar) - Recharge Level: 0% - Rebirth Status: Critical
Rebirth Status Descriptions:
Incubating - Grief Seed is safe for the time being
Looming - Grief Seed is showing signs of internal activity
Danger - Grief Seed is gathering corruption within itself, preparing to re-emerge
Critical - Grief Seed is in the final stages of rebirth, which may occur in the next few sessions
Imminent - Grief Seed will inevitably spawn a Witch in the next available session