[Heroes V] Shalassa Castle

Basically, I wanted to create a 3rd upgrade for the 7th level Avatar of Shalassa. Regarding the environment for the Atlanteans: we'll need to create a new environment, for example, a ford or a lagoon, that is, an environment where a hero from any race could pass through. The balance shouldn't suffer because of the lore; the Atlanteans should be a regular race, not weaker, but also not stronger than others. I found a website for developing new towns for Heroes of Might and Magic III, and it had these sketches of towns.