I've seen a lot of suggestions in other venues as well as here about possible expansions or crazy house rules for this game. I figured I'd make a thread where we can toss ideas around and maybe mash some together. I'll get the ball rolling.
As a chaos space marine player, I'd love to see some kind of heresy-based expansion. Maybe a Shadows Over Camelot style "Traitor" that is assigned at the game's start, who wins by making sure a certain number of people are eliminated or corrupted by the time the game is over, but whose identity is hidden until he completes his objective. Also, it would be awesome to see what happens to characters that succumb to corruption. Maybe have an effect in game of hindering the players after losing their minds to chaos. Perhaps a threat card that forces a player to battle with one randomly chosen character that has retired due to corruption during the game.