The mechanisms by which each land of the Shadowlands operates are quite intriguing. Yet, I have always held a particular fascination with the venthyr of Revendreth.
How they siphon souls of their sins, storing them in strange stones, and dredge up minions from the muck that surrounds them -- it is all quite novel.
They keep their secrets close at hand, however, and will not willingly part with information. I offer trades for any of their tomes you might come into possession of.