Reigen is a very likable guy but his charm makes up 90% of his character. In terms of an actual fight he really wouldn’t last more than a few seconds against Shigeo. The difference in their abilities is astronomical. Shigeo could level the entire town in the time it would take for Reigen to throw a punch. There just aren’t any viable outcomes where Reigen pulls off the upset. Shigeo Kageyama wins.