I have come up with something that seems pretty strong .
day 1 priest
I am priest . everyone send your class to me in whispers please. Prince please jail me tonight and i will pass on those who have claimed and those who have failed to claim . Failing to claim will look very suspicious . Anyone who has not claimed by end of today will be up for execution 2moro.
For me this sets up a very strong position for the blue dragon. Whilst in jail the priest will be safe . The Prince is not outed and those who fail to claim are suspicious . Investigators can be coordinated .
the thing with this tactic is also that it is not limited to a turn 1 play.
you can do it at any time you like as long as Prince and priest are still both alive .
You can even use this the turn after a Prince res if priest still in play .