If mafia (Zim's team....) have no NK, then how would they win? Do you mean that they only have daykill?It may be also this way:
mafia has no NK ability
lone faction has
There are a lot of possibilities. It could be that Zim and Tak had similar powers: a NK that only works on the other player, and Tak got lucky whereas @Gorny didn't. The death of one or the other could be the trigger to open their respective wincons (defeat town). I think this is something that fits the theme and would amuse Leo to watch. What I wonder now is whether Gir's wincon has changed.
Gir, what color are your eyes?