RTF is a global modification that replaces all towns in the game.

Fire is undesirable due to the summoning spells for demons and archdevils.

In the cities of the Academy, from which the elementalists emerged, there have always been many demon worshippers and mages studying hellish monsters. Perhaps without them, there wouldn't even be Orcs! For some time, Biara ruled over humans and undoubtedly cultivated a large number of demon worshippers. Also, in the campaign for Zehir, there was a case of a human hero summoning demons, so it's all quite possible.