There seems to be occasional confusion about the victory conditions of neutral roles, especially with new players.
I suggest that the text on the rolecards is changed to make clear that:
Survivors win with everybody, not just town and mafia.
Serialkillers, Arsonists and mass murderers win with witches, survivors, amnesiacs and executioners, and do not have to kill them.
Right now, the rolecards imply that this is not the case.