Last year, on December 31st 2011 (which for our purposes, was so late that we'll consider it January 1st 2012) I started Mafia III: The Cult. I replaced the typical "mafia" group with a "cult" group. However, this also led to my changing up several other typical roles.
The Detective became a saviour for those the Cult kidnapped; the Doctor could save them before they were kidnapped, and could not be converted, and I even changed the official title to "Medic"(a term that has for the most part remained); and then of course the Cult turned people into new Cultists, increasing their size instead of killing off the other side.
However, I also made one other change: in Mafia there is a role known as the "Arsonist". This player is sort of like a serial killer, in that once every two rounds they kill someone, except that it is fire related, and of course they are only allied to themselves. Sometimes, there is a particular role that protects only from the Arsonist.
I changed the Arsonist to the "Pyro" - a role that was still allied only to itself. However, the Medic could not protect people from the Pyro (in a second installment, I created the "Engineer" role, which could protect from the Pyro). The Pyro would select two targets each night they were active, select a weapon to use on each one (either a flamethrower or an axe, like in TF2), and then the player to die was selected via a dice roll.
Fast forward to today, where my latest game, Bionicle Mafia III: By the Numbers - With a Vengeance has just ended. The Pyro has remained as a role within almost every single Mafia game, sometimes in a more traditional "pick one player, they die" role, and sometimes closer to its original incarnation. In this most recent game, the Medic could save Pyro targets, and the target to die was chosen by an online version of rock-paper-scissors; similar, but a little different. The next game appears to have the Pyro playing some sort of major role - he even shows up in the title! I don't know how Zakaro will use the role, but I think it's kinda cool that a role I actually invented has lasted so long.
So, here's to the Pyro remaining a role in many Mafia games to come.