June 27, 2014 6:52 AM EDT
http://www.uesp.net/wiki/Lore:The_Secrets_of_Ragnvald
This suggests that Otar was corrupted by 'dark voices,' changing Otar from a 'good' to a 'craven priest.' Possibly this is linked to the effect of the mask? Maybe the masks, considered 'gifts' by common understanding, were a method the dragons used to corrupt and control the priests? We know that they were mostly peaceful to their subjects, and then became more cruel, so it could be suggested that the masks had something to do with it, no?
More a role-playing thing than anything in terms of game physics though, obviously.