[quote=@Legend]
<Snipped quote by Yatagarasu>

So what? Shion is really a suppressed lunatic? Her soul grows to fit the body?
[/quote]

A partial soul can still maintain a full body, and I don't know that I'd call it that, but in a sense, yes. My hypothesis is that this is a metaphysical phenomenon similar to your mother's, but also psychologically similar to my own splitting, back when I was whole. Even though my soul was... essentially nothing, as it grew back, so did the parts that were "other" to me. I'm thinking this is a similar thing. There's a lot of things we can search for to confirm that, though.