Chattering Cenobite's real self.

I agree. I thought it was kind of perfect that he was a kid.

I think a lot of people start out relatively decent and then after solving the box, the cenobites nurture a spark of potential in their personalities in order to psychologically transform them, usually some sort of passion or desire, not even something directly related to sadism or depravity. Channard became a cenobite because he was so dedicated to his quest for knowledge that he would kill and torment to further his goals. He wasn't a sadist for sadism's sake, necessarily. Elliot became a cenobite because he attempted to fill the void left in his life with "forbidden pleasures" after experiencing the horrors of World War I. Even then, I doubt he was a monster.