I had a non-player character who originated in one of my first Warhammer 1st ed games called Armand De Guin. I never intended him to be a huge character, but he obviously made an impact.
Armand was the mysterious-guy-talking-in-riddles character to hook the players into an adventure. He was actually a con man pretending to be a man of mystery to con the players into going into a barrow just outside the Moot and they sort of fell for it, even though they were suspicious. The game was a one-off but he lingered in the minds of the players, so much so that a few games down the line when they were confronted with a similar quest into a tomb they sought out Armand to ask him for advice. He became the go-to guy for information. He never popped up cartoon Dungeon Master style and say, ‘You must do this!’ – the players actively sought him out. He would never, though, accompany them on their adventures. I enjoyed playing him but I would never Mary Sue it up.
In time Armand De Guin became a character who appeared in all kinds of fantasy games I ran - I used him as a quest-giver, the guy who gets the players on track, the guy they go to for information or clues as he seemed to know everything about everything, or at least point them in the right direction if they needed it. I used him in three different games with three different groups. One day, one of the players from one group joined another (Warhammer over to MERP, I think it was) and Armand's name was mentioned and there was honest shock at the fact that he was here, in another world. It was then that I realised that maybe that this Armand character actually existed in the game worlds like a constant shadow – a bit like Moorcock’s Eternal Champion – and that he had a some kind of overall plan, that there was a reason that he needed the PCs to do the things that he asked them to do in each of these fantasy worlds. He had a bigger agenda and only the completion of these quests by the PCs could bring his goals to fruition.
I never fleshed that out. The games dwindled, the groups broke up, and the last time Armand was mentioned was a few years ago during a one-on-one game. His plot was never completed and I was never asked why it was he existed in so many worlds, why it was he helped the PCs with so many things and pointed them in the right direction.
I miss playing Armand De Guin. Maybe I’ll dust him off when I get this Dragon Warriors game off the ground.