I'm a bit confused about how the seedborne corruption should work on npcs. My group is travelling with a cohort and Kaklatath, and they are about to camp in the city. So if these two fail the will and fort save, are they waking up seeded and trying to attack the group? I dont see any rules about how quick the progression is.
Just take a look at the stat block seeded creatures on page 91. Seedborn consumption has a onset of one month.
But remember that the PC´s are carrier of this disease as well - they are just imune to it. So the cohort and kaklathat might be infectet the moment, they first get in contact with the pc`s
The stat block of Xamen dor states that there is a 1% chance per year to be targeted by his nightmare dream ability if you know the name of the god and are understanding his nature.
If you are affected by this ability you must do a safe or you are affected with seedborn consumption with no onset. This is stated on page 86/87