Role name: Werewolf
Description: A mad person, infected by Werewolf's curse and willing to pass that curse to someone else.
Alignment: Neutral/Evil
Abilities: Kill someone at night
OR
Special: Once per game, you may infect a single person with Werewolf's curse. If you die, that person becomes a new Werewolf. The infection is passed only once per game.
Goal: Be the last to survive. If you die, you still can win if other Werewolf is alive.
Host Options:
Invulnerable at night: ON/off
Kills roleblockers: ON/off
Immunity prevents being infected ON/off
Target knows if he is infected ON/off
Yeah, i know that this role is based on Serial Killer, but it also has a twist. He is no longer alone, as he can infect someone with Werewolf's curse. The downside of that action is that infection can be removed by Doctors (as long as infected didn't transform into a new Werewolf). Also, the infected target may die before you on some occasion, so keep that in mind. If you infect a Mafia, Mason, or Cultist, any of their teammates will notice who becomes the new Werewolf. Even if that Werewolf will try to kill his former teammate at night, he may still leave his last will.
The person who becomes the new Werewolf can be even more dangerous than original one. As infected person, he is now affiliated with Werewolf rather that with someone else. Even if the infection notification is on, he may not speak about it to Town to avoid Doctor visit. When turned in a new Werewolf, he may choose not to kill anyone at night, leaving the Town to believe that all werewolves are gone. Then, once the game reaches its climax, he then comes for a surprise kill!
On a special note, if one of the Mafia members becomes infected, they can warn the rest of their team at night and then call of a Doctor's help at day. Then again, the infected person may not speak about his infection at all and may try to make a win for Werewolf and himself, rather than his Mafia teammates. Same thing can happen with Masons and Cultists, so there is no telling how infected person will react! If infected person is cured by a Doctor, he becomes affilated with his original side.
The optimal targets for infection should be people that are bored with their current roles. The list includes Citizens, Survivors, Coroners, Jesters and maybe even Doctors. More surpisingly, you can also infect a revealed Mayor, if he cannot be healed by Doctors or if you think that the Doctors are already dead.
Personally i'm fairly sure that if this role becomes implemented, he will replace the Serial Killer in most game setups.