DB chapter 34 page 323(pb)
"we smile at one another and play nicely all in the name of Kemmler's greater glory, of course. ......."
Chapter 8, p98.
"Get your own book, Kemmlerite."
"I have nothing but disdain for the madman Kemmler."
"Is that what you're doing, destroying copies of the book?"
"Time has taken most of them. We have accounted for the rest." (K)
"Is it not enough that Kemmler's disciples could use this knowledge for great evil?"
"Grevane and the Corpsetaker are madmen. They must be stopped." (K)
"Do you know why Cowl has made a study of necromancy? [...] Necromancy can be turned upon it's nature[.] Life can be served by that dark power, if one's will and purpose are strong."
"Grevane and the Corpsetaker are determined. I intend to beat them to the prize and use it to destroy them. It's the only way to be sure one of those madmen does not become something more terrible than the Earth has ever seen."
Cowl does imply he's met Grevane and Corpsetaker before. But I think it's clear he was never a mole in any meaningful sense of the word, and very unlikely he ever worked with Kemmler, even as a spy.
We saw that Grevane immediately leapt to the conclusion that Dresden too was a Kemmlerite working towards the same purpose as the others just on the basis of Dresden's aura or magic being tainted. It seems fairly clear that Cowl never worked with Kemmler, or was ever any kind of mole - the actual Kemmlerites just assumed he was because he was going for the Darkhallow, so they assumed he was acting in Kemmler's name. In actuality, Cowl intended on stopping them himself - not because he actually wanted the power for himself, but because he was convinced the Darkhallow was going to happen, and it had better be him there rather than one of the crazy Kemmlerites.
That's important because even though Cowl is a student of necromancy, it's clear his aims and purposes are very, very different than Kemmler's. On the other hand, I think it's important to note Cowl
never actually used necromancy once, and his apprentice (?) Kumori only used it to revive the dying guy.
Indeed, in DB at least, I'm almost inclined to believe that Cowl was working at cross-purposes to the BC. The BC (we believe, anyway) has taken every opportunity to throw the world into chaos. Cowl not only seemed intent on stopping (world-wide, not Chicago-wide) chaos and destruction in DB, he alerted Dresden to the corruption on the White Council and clearly seemed to oppose it. He refrained from using black magic at all, and Kumori did only once. Those affected by the BC reek with black magic (the hexen wolves, the curses and rituals.) He seemed mostly reasonable, and spared Dresden many times, even though Dresden's stopped BC plot after BC plot. He's even out there burning books written by a known BC operative, Peabody.
Either way, he may have been BC-aligned during DB, but he wasn't a "mole" and it seems unlikely he ever hung out with Kemmler.
Isn't there a WOJ that some of the people we think are bad may not be? Thinking more on it, Cowl also would have eradicated the White Court vampires if not for Dresden, and we simply don't know enough to judge what the athame situation was about, especially in light of Mab's alleged madness.
