This suggestion is only viable for an FM. However, I was thinking for a game with 13 players to add a fourth mafia. This "fourth mafia" would know all of the mafia roles but be town aligned. It would be strictly written into the rules that the Undercover cannot type out all of the mafia. Furthermore, the Godfather can kill any mafia member he suspects of being the Undercover free of charge.

PMs (if allowed) must go through the host and any PMs from mafia members are seen by the Godfather, because he's paranoid and has bugged the mafia's compound. The Undercover wins if the town wins. Otherwise, the mafia wins.

Other than that, any and all rules of mafia would remain the same.

Is such an idea workable into an FM? (I know it's absolutely not workable into the Sc2 mod.)