User blog comment:Yoponot/Fall Fanon Con 2016 - Ultimate Writing Results/@comment-24922135-20160929233957/@comment-4969948-20160929234625

I believe CaT is referring to the ending and the overall descent into insanity (which was my purpose).

As for the part you're confused about: he's saying "The Devil" did it, but then he stopped and corrected himself and said "I" instead because he's realized that he is the Devil in this scenario.