Dacian Dubois is the youngest son of a family that has risen to some prominence in a rather backward part of Montaigne. He’s a reasonably handsome young man who attempts to emulate the dashing cut of a duelist. Any real master of the blade can see he is a fop with pretensions. As the youngest son of a wealthy family doted on by his parents Dacian has never wanted for anything. Dacian has a bad habit of talking about himself in the third person.
Dacian wants adventure. Dacian wants to be the greatest swordsman in all of Théah. Dacian woos the ladies. Dacian drinks his fellows under the table. Dacian truly believes in himself. Dacian has never faced a real challenge. Dacian has never dealt with the consequences of his actions. Dacian has never applied himself.
The upshot of this is Dacian can woo the local girls and boys but will find himself out of fashion if true heroes are in the area. He can beat any of the local competition in a duel but is no match for even a moderately talented fencer. Against a duelist he is in serious trouble.
Dacian knows more than he realises and he will often accidentally let something slip either to try to impress a hero or when they have undone him.
Dacian may have older brothers who can actually fight a bit but they are away most of the time. He also has parents who have some influence and plenty of money (represented by his influence which is his by association rather than influence he has earned).
Dacian fights duels (to first blood) for any perceived cause. As the best swordsman in the backwater area he has never lost. This will result in him trying to find a reason to pick a fight with a hero who is passing through.
Should a hero rescue one of his conquests he will feel threatened. He may plot to cause them trouble with the watch. He might spread rumours about them. He might tell a real villain where they are.
Dacian may simply bumble in to the middle of a bigger fight getting in the heroes way.
After being beaten Dacian may try to get one of the heroes to teach him to be a better swordsman.
Dacian may follow a group of heroes around in the hope that he will be able to enhance his reputation.
Dacian may (in private) beg the heroes to take him away from his home on their adventures. He will offer to pay his way. To do so he may steal things from his home. If caught he will blame the heroes.
Dacian will keep showing up at the most inconvenient times.
Dacian will also show up with a small band of followers when the heroes have a whole army to chase him off.
Dacian as I’m sure you’ve worked out is comedy light relief.