I like the idea of both characters, honestly. I never really considered the idea that Uialien could have some sort of stress response that causes them to age and waste away. I actually... think that's incredibly awesome and makes a lot of sense. It's sort of like how a lot of stress can drastically age regular people except in this case it turns an immortal mortal. 

I can't make this decision for you, unfortunately. I think both are logical choices. You could try getting a coin and assigning the Uialie to one side and the Calva to the other. Then you flip it, and when it's in the air, you should pretty much realize which one you're hoping for the most. It's a pretty solid trick to figure out which way you're leaning toward the most. You could also do it again for which race you'd rather play. 

Also, you're not limited to one character. If you want to make two, that's fine. Just post them in two different posts so I can link them separately in the first post.