Unregistered

i was wondering if anyone knew how to complete quest #107 called "off the record". its after you become a paladin with the same guy who allows you to become one. the quest summary is as follows "...your task is to defeat three infernal armours-found in Gerzuun-with damage deflected by the Pincushion ability." i have tried using the ability but nothing happens. if someone could figure out how to make it work, that would be greatly appreciated.