Antagonist idea: The Follower

[The Grim Sleeper]

Would it need to be an actual antagonist? Why not an NPC who follows the same basic rules, ala the strange figure from the King in Yellow?

I too like this better as an game-event, rather then a player-role.
Making a whole antagonist role requires lots of code and lots of balancing, just so that one player can get stuck playing a weird version of the wrath.
But as a game mechanic, this is very simple. It would be just like THE SHARK, but when you fart on somebody's face, it switches to the new target.