Alright, I've posted a quick description of each King. They were not the nicest people.
Basically, the cults don't worship them directly - instead, they find people exhibiting the appropriate powers, claim them as the reincarnation of the appropriate King, and quietly revise some points of their scripture.
The idea here (the Seven Crowns part) is essentially an attempt to make some setting the same way that ToB did setting - through descriptions and sideways hints, rather than concrete timelines or explicitly laid out geography.