Tihewgoe is a dark god of nightmares. Not the darkest and definitely not the biggest, but still a god in his own right.
I had me a dream once. Just after I *acquired* this here knife. Only the knife was a bit shinier and I was in an alley somewhere. I dunno, maybe it was Brie or Holsten, someplace like that. Anyways, I'm walking down this alley when I comes across some dumb bloke trying to shortcut his way to market. Like *my* alley is a god-d**ned thoroughfare for just anyone!
The PCs find a strange helmet, when donned it will take control of that PC and speak and act trough him/her. It explains that it is benevolent and needs their help in a quest and that it will stop possessing the PC when the task is done. Great if a player is gone for a number of sessions.