Nick Gevers: It occurs to me that when Typhon's personality was scanned to create Pas, there could have been an accidental--or even deliberate-- incorporation of elements of Piaton's mind too. Thus, perhaps, the unexpected (relative) benevolence of Pas and his Plan.
Lee-
This is an interesting alternate explanation. I think most have been content with the idea that the benevolence is a result of the principle that we tend to become the role we play. I wonder if it will appeal to those readers who prefer nuts and bolts explanations over literary ones.