can a reason & magi region be combined?
reason & farie?
or reason & devine?
"Reason" no longer exists, what books are looking at Abe? Got your hand on an Ars 3? I use to own at least three- can't find a one of them. I digress.
Regiones are unique supernatural areas. Some of the old books discussed locations where multiple auras existed at the same place. For instance a place of pagan worship that became a place of Christian worship. One certain days the location may have a magical aura. On other days it might have a divine aura.
On the days when it has a magical aura one could attempt to access the magical regio. On the days when it has a Christian Aura, one could attempt to access the Divine aura.
The regios are a manifestation and aspect of the aura from which they come. They are not a merger or shmear or blending because while the two aura coexist they do not exist 'as one.' Therefore, I would say "No", they can't be combined. Though they may coexist.
Now having said all of that, this is all based on editions prior to Ars 5. I've only just purchased Realms of Power Divine and am not familiar with it enough to say if the above is still valid in Ars 5. I suspect the information is still valid, but these locations where two auras exist are considered very rare. There fore the likelyhood of such a thing occuring is low.
What is most important Abe is what you want to do with it. It's your game, make an Aura that is True Reason, Magic, and True Nonsense if you like. But what good comes from that? If it adds to your game great, if it's an exercise in what if's, well why? To what end? I hope these questions have a practical application at the gaming table. Have fun.