[Sombre]

I have a lot of ideas scribbled down for a thread like this. At home though.

For now:

What about a unit buildable/summonable only in the sea, which is amphibious and has #landshape of a non amphibious form - representing a larval underwater stage moving to an adult land only stage for instance, merfolk shedding their tails for good etc - it also works the other way around, with one way transformations when a unit goes in the water, or even the first time they go through a forest.