Perfect! That was exactly what I was searching for, and I followed the trail of bread crumbs to the analysis of SmF in light of CD. Butcher truly never ceases to amaze me with the way he manipulates Harry and keeps him in the dark, an unreliable narrator: note how Harry assumes that 'contamination' = a member of the Church taking up a Denarius, but after CD, Nic's comments make far more sense as describing Nemesis. Dresden is so fixated on Denarians at the moment, and knows nothing of Nemesis, so his logic, which is based on a flawed premise, leads him to an answer that is far too limited in its scope. Most importantly, Nicodemus neither confirms nor denies Harry's assumption; rather, Nick's remark about common interests makes perfect sense in light of what we know about Nemesis and Empty Night.

What about the accepted theory that the Erlking was responsible somehow for the hexenwulfen belts? I haven't been able to find that post anywhere.