So I said I was finished with my quest system...

[Dr. Spoon]

well as far as having an npc show up on a specific map
after a certain set of requirements is possible..
using the old source code i released a long time ago
in that one i had npcs that only showed up at night time..
that system could easily be adapted to
show any specific npc once a certain conditions have been met

the source code is still around here some place
it may help but hey its just an idea