Originally Posted by
CosmicKirby
You haven't seen the spirit possessing another race's body yet, but that certainly doesn't mean that it's not possible.
And what would happen in this instance? That's a good question, that would be answered when/if it happened. It could work in any multitude of ways, either altering the new host's body, or not altering it at all.
If I recall correctly, the last thing the Sahagin chief had was a bullet in his brain, by your logic the new Sahagin should've been the proud owner of one as soon as he was possessed. So clearly, the consciousness, or the soul, is the only thing that's transferred.
Lore functions to make the world consistent. If the changes made to it are also consistent, then it's functioning perfectly as intended.