Sytgian guards are buildable Demons with waterwalking. They are not upgrades for Drowns, largely because the extra strength for Drowns from stronger units could not carry over. I think having different racial promotions caused issues anyway, and there was never a lot of lore behind allowing the upgrade. You are right that with strong drowns their role is diminished though. I think I will allow them to cross Oceans (not just coasts) without any tech prereq, while Drowns still need Theology to go there. I'm thinking of making them resistant or even immune to Psychic type damage too, and maybe giving them the Boarding promotion. Any Crazed unit in a city with an Asylum can already use the Commit to Asylum spell, which replaces Crazed and Enraged with the Committed promotion. That should let them stay put in the city, but is replaced by Crazed and Enraged again whenever they leave the Asylum. I already have it coded so that any Enraged unit has Crazed and Enraged replaced by Committed automatically when they are built in a city with an Asylum. I'm not positive when I made that change, so it might not apply if you are not up to date, but in the current version that means any Lunatics trained in cities (rather than upgraded from slaves outside of cities) should stay put in the city until you move them out. The Runes of Kilmorph is associated with earning gold through honest hard work, but the Undertow is associated with coveting gold and exploiting people for their riches. It is a Mammon/Hastur aligned religion. I just got to thinking that giving the Temples of he Undertow extra gold from water tiles would be an incentive to spread the religion and build temples but no incentive to actually convert to the religion early in the game. It might be better to make Asylums grant extra gold from water tiles, which could help balance out the unhappiness the building causes. It would probably be more thematic too, as asylums could earn more money exploiting those whom the seas are driving mad. I could make it apply to river tiles too, as those are still a source of rivers and would help out some cities further from the coasts.