With regards to the AI, spells are cast as explained in this thread,
https://forums.elementalgame.com/438446
"they are in nearly every file under the english data section, everywhere you see an AIpriority tag and a value, that is the weight some decision algorithm assigns to that game element. Spells, equipment, and traits each have these. CoreAIDefs.xml has the weights on the main game ideas. Hundreds, maybe thousands, of what look like hand-picked weights. So the idea is that game comes up with candidate actions by applying these weights and applies the decision with the highest value. I didn't find the algorithm that computes this, but picking the weights amounts to determining the policy, so the rest is search. The behavior is set with these weights."
There are 66 xml files in my English directory, but only 7 of them contain AI priority:
CoreAbilities.xml
CoreAIDefs.xml
CoreArmor.xml
CoreSpells.xml
CoreWeapons.xml
CoreWorldResources.xml
Treaties.xml
There are 990 instances of the AIPriority element in these files.
The use of the element in CoreAIDefs.xml looks different from how it looks in other files - 71 of those, with 22 unique values of the InternalName attribute:
Arcane, CityBuilding, CityDefense, CommandPost, ConstructionTimeConcern, Crystal, Economy, Expansion, Farming, Food, GoodieHuts, Housing, Merchant, Metal, Prestige, ResearchTimeConcern, Shard, Shards, SovereignProtectionFactor, Study, War and WorkShop.
CoreAbilities.xml defines the level up perks.
CoreSpells.xml defines the spells and would be the logical location for any mountain creation spell, so I took a closer look at it:
There is one strategic earth5 spell: Earthquake, but it needs a city as a target.
There are two strategic earth4 spells: Destroy Land and Summon Earth Elemental. The description on Destroy Land reads "Plunge land or mountains directly into the depths of the sea." That is a new one for me but it looks like this one is available only to certain sovereigns.
There are three strategic earth3 spells: Lower Land, Raise Land, and Set In Stone. Set In Stone is a city enchantment. Lower Land has the description "Turn mountain into hill; hill into land; but not land into water." and Raise Land has the description "Turn water, beach and cliff into land; land into hill; but not hill into mountain."
There are three strategic earth2 spells: Cloak of Thorns, Stoneskin and Tremor, and three strategic earth1 spells: Aura of Might, Enchanted Hammers and Nature's Cloak, but they are not high level and do not change terrain.
Also, looking for any mention of spells that mention earth in any way, I get this list:
Aura of Might, Cloak of Thorns, Destroy Land, Earthquake, Enchanted Hammers, Lower Land, Nature's Cloak, Raise Land, Set In Stone, Stoneskin, Summon Abomination, Summon Earth Elemental, Summon Familiar, Summon Titan's Imp and Tremor.
Anyways,, the claim that there was a high level spell that did this was from Frogboy and I am not in any position to dispute him. But if there are such spells it looks like they are buried in the game implementation and not defined as a player accessible spell. Still, if Destroy Land is spell that follows the same pattern, it's likely only certain sovereigns can access the spell and then only if they get the right levelup perk.
So I went poking into the dll and exe files, and I found two of them that had strings that correspond to the internal names of these spells: DataZip.exe and FallenEnchantress.exe. Interestingly, neither of them seems to have the full set of internal names, and they both have exactly the same set of internal names:
Earthquake
LowerLand
GreaterLowerLand
RaiseLand
GreaterRaiseLand
So it's looking like there's a Greater Lower Land and a Greater Raise Land spell, and I imagine that Greater Raise Land can create mountains. But since it's not listed in CoreSpells.xml I think it's not something that players can use. (But I find it odd that none of the other spells are listed in FallenEnchantress.exe -- I'm sure that I've seen AI Sovereigns with Stoneskin, so I do not know what it means that I can't find the spell names listed -- but perhaps it means nothing since executable files are strange things).
Edit: yes, going back, I see that GreaterLowerLand is an attribute of the Destroy Land spell. I also see that Raise Land has an explicit list of which terrain types it applies to, so presumably it could be applied to hills in hypothetical situations not constrained by the current CoreSpells.xml reference.