" He didn't mention the other part of the book. That following the heroes when they set out was the tenth member of their party. A broken creature who went through all the same dangers and trials, who had made a single bad choice and taken up a power he didn't understand - and who had become a demented, miserable, living nightmare because of it. In the end, he had been just as necessary to the overthrow of the darkness.
But he sure as hell didn't enjoy his part. "
― Jim Butcher , Changes (The Dresden Files, #12)