First of all I was wondering whether its Madara or Obito who helps Itachi with the Uchiha Clan Massacre, then I'd also like to know which one (Madara or Obito) was the one controlling the 4th Mizukage. Also if someone could put these events in order, and the approximate time between these events, Uchiha Clan Massacre, Uchiha control over the 4th Mizukage, When Obito "died", When Obito seeks out Nagato.
obito dies in the collapsing cave then is found by madara who is pretty much dying. as madara gives into death he then gives obito the order to recruit nagato and this is about a decade after madara implanted the rinnegan into nagato. a few years later i believe obito starts attacking villages and kages such as the 4th mizukage and hokage. then obito helps itachi in the clan massacre.
i believe thats how it goes