Than their would be no war, nagato would have most likely ended the whole thing since in terms of mastery over the rinnegan nagato shits on madara and tobi like 25 or 30 years, not to mention nagato could have been the one to stop the juubeis revival since he has the ability to control gedo mazo just by being of senju lineage ,he could have stop kabuto and done it WAAAY easier than itachi and sasuke but than he would have died to, nagato would have obviously destroyed sasuke if he ever posed a threat to him, with human path he can easily take out the soul of any edo he wants to simply by touching them(which is why i say a rinnegan user is a edos worst nightmare since edos need a soul binding them )he could have been a most worried asset to kakashi,bee,naruto,and gai,(with nagatos help they would have struggled a much are they are now)so nagato could have made quite a difference if he were hit with kotoamatsukami instead of itachi, much bigger than itachi thats for damn sure.
