You can bring them back to their previous values using standard methods. Otherwise, in most cases, the observation made by the Heroes player is correct.
All non-player characters are "GM characters," and the possibility of killing them varies depending on what they represent.
The entire country, except for the coastline, is surrounded by a wall, and it's not that easy to pass through it.
Ничто не возникает из ничего и ничто не пропадает бесследно.
Если где-то чего-то убудет, то в другом месте добавится.
(Закон сохранения).