I've never heard of this. Though, I have found Reaper Soul Fragments, but never found out their use. And I thought I discovered everything in the Soul Cairn. Well, then, thanks for the info. Looks like I am going back for another adventure into the Soul Cairn.
Yeah - there was more going on in the Soul Cairn than I realized, too. Weird fissures, portals, glowing crystals, lightning rods, a merchant, the whole soul husks thing - I felt like I was in a Tim Burton/Neil Gaiman-ish nightmare.