Agree. The devil's a really good character in this. I'm a person who likes a happy ending so I was a little bummed that the narrator didn't find a way to turn things around. Other than that, I think your writing moves and your sense of story was good, excellent flow and twists. I think this story could benefit from some copy editing -- streamline some of exposition and even some of the narrator's dialogue. In other words, you could tell the same story but make it leaner, which would place more of an emphasis on the devil's revelations. Maybe also give the story more of a sense of time and place - I couldn't visualize the kid's room or the geography of the house. But those are minor and fixable. I think there's a very good story in here. Nice work!