I very much like the general appearence of this hack, especially the region which I think is very well structured and balanced.
1 piece of criticism though... you do realsie that the 3 regis are meant to represent human history? ie.. Stone Age, Ice Age, Iron Age. They don''t represent elements. Therefore Regifire puzzles me somewhat (though it is designed very well!). The Regis were meant to be built by humans ( see here
https://bulbapedia.bulbagarden.net/wiki/History_of_the_Pokémon_world) and how humans built stuff from fire I do not know. Maybe you're trying to represent the human discovery of fire? I don't know.
Hack looks good! Keep it up!