Re: whatever happened to these characters?
They do appear in A Singular Destiny
and Gomez and one other character who I can't remember right now, make brief appearances in Indistinguishable From Magic
(although this is apparently no longer part of the novelverse continuity).
Over the course of many encounters and many years, I have successfully developed a standard operating procedure for dealing with big, nasty monsters. Run away. Me and Monty Python.
Harry Dresden - Blood Rites (The Dresden Files #6)