Who would win. The being that can pass between dimensions? Or the guy who can kill you literally by looking at you? Leaning toward Itachi here. If we equalize a bit, so that Itachi can see and touch D4C (Which wouldn't make sense for this poll to exist if he can't), and that his abilities work regardless of if D4C has chakra or not. But even then, if D4C DIDN'T have chakra, Itachi might still win.