Jack decided that he would unless a new disease on the world. Obviously he wanted the disease to be something out of his fantasies and something that involved physical and/or mental transformations. He also figured that this would hide the fact that its something magical and to keep from people finding him to be the source. Also he could make observations and it wouldn't seem weird that he was taking notes. He could also interview victims without fear. Thoughts went through his head on what disease he should unless and also who it would affect. Would it be just men? Women? Kids? All of humanity? And how would it spread? And more importantly what would the disease cause? Age regression? Animal transformation? Shrinking? Genital enlargement? His dick was enlarging as he thought about that.