Immediately Vanitas tenses up. Out of everyone he's faced, no one's really bothered to ask him that. What he wants to do is storm off because implying that it hurts on any level disgusts him. Rather he gets disgusted with himself for being easy enough to read. Admitting the reality of it also paints him as weak and he'll not have that.

"I feel it," he answers, very carefully. "When they're defeated they return to me. They're my emotions. Like a heart that's been freed, they have to return to the source."

Vanitas isn't going to answer anymore than that.