Odd and Idea - and I guess, wonder.

So, I guess in this story I'm Odd . . . .
So, as a child Odd has a nanny who practices some form of voodoo and she herself at a young age begins to learn the ideas of it and so on. When Odd is old enough to read she begins finding out about all sorts of magicks and religions. That is Odds general background. (skip back to Odd as a 5 year old girl) So, She has this friend who . . . looks like her and laughs like her. Her name is Idea. Idea plays with Odd and they watch tv together. Best friends with the same face. Only problem is Odd is the only person who sees Idea. Odd and Idea have a fantastic relationship but as they get older together, Idea becomes hateful. On thier thirteenth birthday Idea jumps into Odd's body and beats her with her own hands. Then hours later she is the same sweet solitary Idea. There after, Idea begins beating Odd both generally and by pocession. She is drawing pictures of demons and leaving them places and of just strange things. She is screaming while Odd is trying to rest or study.

No for the wonder . . . I thought maybe this being is a kind of servitore (sp) . . . but maybe you have better ideas?

I have never had a servitor jump in my body so someone else can address this if this has happened to them. Other than that it could be a whole list of anything and you would have to elaborate a bit more.

I don't know what kind of entity grows and changes like it did. I've been researching and asking for like 2 years about it . . . . what would you need to know? I'm not sure what would be helpful.