In one of the Q&A's Jim did at Dragon Con, someone asked Jim if he ever considered writing a short story from Donald Morgan's POV. While Jim didn't completely dismiss the idea, he said such a short story would be something of a downer because Morgan's personal history was very dark. Specifically, Jim said Kemmler killed Morgan's parents and the rest of his family. Anastasia Luccio rescued Morgan. Unfortunately Jim didn't give any other details such as how old Donald Morgan was at the time or why Kemmler went after Morgan's family.
I never realized how far Jim had worked out Morgan's backstory. I wonder if sometime in a future book Anastasia will fill Harry in on Kemmler's history; I mean in more detail than Bob did, and her personal history of dealing with him and his followers. Kemmler may be gone for good; or maybe not, but I'd bet dollars to donuts his legacy will play a major part in future events.
Here's a link to the video:
https://www.youtube.com/watch?v=bQDTvMv1otI&t=15s