The Nemeses are a troupe of wandering assassins. They are not just any assassins, however. They only target those who have commited horrid crimes and gotten away with it. They are spoken of only in whispers, and many think they are only myth. They are very real, however, and they're never wrong, and they never miss. They work by mimicking ghosts and figures from the past to work on the target's conscience (or what's left of it). It isn't uncommon for the target to go insane before they die.
There are four members of the troupe.
The Storyteller - He is the herald of the Nemeses, and the last chance that a target will get to atone for his or her sins. He is a fairly attractive young man, and a self-proclaimed writer of tales. He is also an eternal optimist, and a tad naive. He would like to believe that people are inherently good; however, his work is proving otherwise. He will warn a target of the danger in one way or another, and attempt to convince them to sincerely atone for their misdeeds. The "sincerely" is the key part. It won't work if the target doesn't mean it. He has a very strong moral outlook, and doesn't always agree with the rest of the troupe about who they target and who they don't. It was also due to his insistence that targets are given a second chance at all. He may warn someone outright or perhaps play the part of a warning (this could happen to YOU!). Whichever way, his aims are the same: give the target the chance to repent. He will not actively assisst the troupe in an assassination if he has not satisfied himself that they deserve it; in one or two cases, he actively opposed them. He sometimes annoys the rest of the troupe, but he can't help it, and they realize he generally has a point.
An example: Once the target was a pathological killer, who took pleasure in murdering anything and everyone. The Storyteller encountered him, and rescued him from a supernatural foe (in reality, one of the other members of the troupe). As they were trying to escape, they had to cross a narrow footbridge. The boards gave way (by design), and they fell. The Storyteller ended up hanging onto the killer, who was hanging onto the bridge. They couldn't both get back up, and the killer was losing his grip. The Storyteller gave him the chance to promise never to kill again, and to do penance for the killings he had committed in the past. The killer agreed, and the Storyteller let go, allowing the killer to scramble back onto the bridge. (The Storyteller was pulled out of the river by the rest of the troupe, and was never in real danger. If the killer had meant it when he agreed never to kill again, he would have been spared. However, he didn't.)