I just played a long game with Altar and I got the Shadow world spell. Since this spell is rather special and could be fun, I will make this seperate post about it.
Bugs:
-Even after a portal is destroyed, you pay upkeep for it unless you manually turn it off under enchantments
-Its very hard to know which portal to disenchant if you have more than one and one is destroyed. All you get is some x and y values, but I dont know how to find this on the map.
-The cooldown time in description doesnt (and shouldnt work). It says cooldown 50 in the descpription and that would be horrible if it actually was true.
Issues:
-Its a perfect spell for harvesting exp. Cast it near your best army and level them like never before.
-The beasts does not attack cities ever as far as I have seen, and that reduces the coolness of the spell A LOT. I have seen the demon armies next to cities many times, but they do not touch. Therefore the spell is more of a novelty than a real weapon. Can be used to block a path to your empire mayhaps, by filling a valley with monsters.