After killing his father, Toby spent the whole time, before even thinking about you. You were the only person that cared about him. So he spent the whole time wanting to give you a reason to be with him. To depend on him. So what's better then killing your parents? Taking away your job. So when he takes you, there's no reason for you to leave. So when he did, he was going to make sure that you never left. And he was gonna make you believe that he was all you needed.