True Name: Unknown. He is the embodiment of the legend of Jack the Ripper, but as the killer's true identity remains unknown, he has no knowledge of the actual person behind the legend (in fact his wish is to know his name), He is a completely different person from Fate/Apocrypha's Jack the Ripper.
He has no true appearance, and as such can take the appearance of anyone or anything, at one point taking the appearance of a little girl that looks similar to Fate/Apocrypha's Jack the Ripper. He usually appears as a wristwatch per Flat Escardos' request.
