Found one reference but not the one I looking for. 3.5, Faiths and Pantheons. I don't remember family members being mentioned (although Kanisatha has read more Faerun novels than I have and is probably correct)
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Those wishing to access the Adumbral Calyx must first contact Rimrus, who instructs them to bring a live captive to his ship. Once they have arrived on the isle, prisoners and supplicants are taken to the lighthouse and the main access point to the Plane of Shadow, found in the tower’s lantern chamber. Upon a person’s first visit to the Calyx, he or she is expected to take their prisoner to the Black Aljibar, a pool at the center of the shadow pocket. There, the peti- tioner slits the prisoner’s throat, draining the blood into the dark well. When the prisoner has expired, the body is tossed into the Aljibar, where it is consumed by swirling shadowstuff. Anyone unwilling to take the ceremony to its final conclusion is sacrificed, as well.
