Laurence Claxton is confused. For 6 months now he has wandered the countryside becoming increasingly detached from reality. He fluctuates between periods of revelatory spiritual enlightenment (during which he believes in the certainty of his salvation) and times of crushing despair when he is paralysed by the certainty of his assured damnation.
His appearance reflects his state of mind(s): his attire, ostensibly that of a dandy (all fine black silk and velvet), shows signs of serious wear, being soiled, threadbare, and torn. He has not washed in months.
He will be courteous (to the point of fawning) or foul-mouthed and loathsome, and there is a chance (1 in 6 with whatever modifiers the DM deems appropriate) he will attack the PCs on sight.
If encountered he will approach the PCs and attempt to engage them in a spiritual debate (even if he has already attacked them). The slant of his argument will depend upon his current psychological state (50% chance he is assured of salvation or damnation). He will offer to join the party and can be added as a henchman for no charge. He acts as a level 2 Cleric (give him 9hp and something useful like Cure Light Wounds) but the party will incur a penalty of -2 on all attempts to move quietly and to all CHA-based checks due to his strange (and loud) behaviour.
Each PC must pass a CHA check every day; failure means Claxton’s ranting drives that PC (or PCs) to attempt to murder him, with the associated implications for alignment etc.
Assume he’s wearing the equivalent of leather armour, and that he’s carrying a medium weapon (whatever suits your milieu – I’d suggest a rapier and flintlock pistol).