nobody is gonna listen to me because i'm new and all. But I think all of these guys with EMS and their techniques only up until acquiring ems, Itachi and obito win. First off how does sasuke get ems if itachi is alive, healthy and has it? That aside Sasuke has nothing that can get passed the yata mirror, you already know itachi can beat him. Madara would take both itachi and obito to take down but then (and probably only then) that is possible. Although itachi would know of madara and madara would be at a handicap of not knowing itachi's boss-ness.
and Obito was scared of itachi, Zetsu even said that itachi with his yata mirror and tosuka blade was pretty much unbeatable. Itachi with ems and who knows maybe kotoamatsukami? Yea he probably could solo