I've always liked the theme of the Guardians SK wove into the story, and have been wondering about the nature of them.
We only really get a good look into Shardik and Maturin in the DT series and at first both seem to protect their portals in different ways - Shardik in an immense physical sense and Maturin through coercion and mind control - or is this mislead? Perhaps Shardik also possessed similar powers through little statue conduits etc but the infection in his brain prevented this kind of thing from working.
What are your thoughts? What (if any) information is there about the other 10 guardians? Would you like to see more of them in linked books in the future?