I'd say that Eldar might feel "uncomfortable" around a null rod, but if every member of their race doesn't have Psyker, then these aren't adversely affected beyond that. If you have the kind of null rod that saps synaptic patterns of the wielder over time, and then an Eldar holds it that long, same thing as anyone else.
As for saving DE's souls, hell no. Slaanesh is absolute crap, and probably my least favorite Chaos God (TT's fault, damn broken 4E Noise Marines), he is still a Ruinous Power and that makes her ignore most of the rules. No "mundane" apparatus can shield their souls from the withering, and living in the Webway doesn't help.
My little confusion stems more from "what damages the souls of NEW Dark Eldar?" Slaanesh's birth tore the souls of many Eldar to bits, and many who survived have them slowly bled (Asdrubael Vect might be that old), but what harms the newly created soul of a newborn Dark Eldar?
Edited by venkelos, 11 January 2014 - 04:07 PM.