Nothing quite like this.. we've had villains we had trouble tracking down, but there was always a trail.... the akumas, they have to come from somewhere, right? [he's getting excited now, a possible idea forming]

They're what he uses to turn the people into these things, right? So they must have to reach the person first, so... you need to find some way of seeing where they come from... It'd be difficult, you'd have to set up some kind of surveillance, it might take multiple victims before you can really pinpoint where they're coming from, but every one you see you get a better idea of where it could be coming from until you can narrow it down... does that make sense?