I just found a lightning attractor in the Soul Cairn that wants one of my soul gems. What is it for?
EDIT: It took one of my grand soul gems, and then created a black soul gem - after which, the lightning rod retracted. Very cool, but I hope it's reusable.
DOUBLE EDIT: if anybody is wondering where it is, it's due south of the "road" going up to the castle where Valerica hangs out. It's just a small lightning rod onto of a building, with a soul gem "cup" attached. --- XBL Chris616263| Give a noob a fish, and he'll beg 4 moar plz. Teach a noob to fish, and he's an elitist jerk for the rest of his life.
I think they might be tied to the Reaper's Lair. I've taken down four of them and when I placed all the Reaper gems lightning would come crashing down from the ceiling to the floor. I think if you take them all down it might do something in conjunction with the gem.
Admittedly this is a guess because I can't really find any more attractors but that doesn't mean there aren't more.