Chatcaavan Shapechange

Details here about how the shapechange works.

Details

Shifting is a skill like a martial art - not everyone is capable of the same shapes. Just like the capacity to be an Olympian athlete is possible to all humans, but is in reality limited by training and aptitude and vicissitudes (whether you're born with certain setbacks).

So something like a Naysha might require the equivalent of a Master's level of skill, while a Flitzbe might require an Adept-level, and there might only be 5 or 6 people in the entire Empire who could pull it off.

The Breath of the Living Air is inevitably an ambassador, because to learn new shapes requires befriending new species.

Biology

This is where I put stuff like whether injuries/scars go with you into different shapes.