I'm not quite suer where this asylum-goer skin-fetish comes from.. maybe I'll get it in a short while...
Anyway, I think that skin is not really in the question... I do, however, like very much the idea of the soulless' souls being made to Mahir. I think it's very efficient (albeit much more so than the average necromancer noramlly bothers to be...), although I would imagine a sort of soup-cauldron method, the souls being all sucked together and condensed, boiled, treated, dried, chewed and so forth together with three large eggs, then a measure of the concentrated negative emotions (I have a feeling that the last thoughts going through the mind of someone having his soul stolen would be far from fluffy) being then put into a mould/arranged on a greased oven tray/kept until ripe in brightly-coloured glassware/whatever and Poof! you have a fresh batch of Mahir, ready for torture, draining, world-class Hide-and-go-Seek tournaments, best with a small helping of cranberry sauce. I imagine the draining bit is something to do with keeping strong and capable of existence or something...
Well, something like that, anyway...