As hilarious as this is that Obito is Tobi, it still reiterates how terrible of a job Kishimoto did at building up to this point. Either he went for shock value in attempting to throw such a ridiculous (yet predictable) curve ball, or he forgot how to develop his villains in a meaningful way. There better be a damn good explanation for this.
Didn't the 4th become Hokage before Obito *died*?
I could've sworn in the previous Kakashi flashback, Kakashi became the group leader, and the 4th goes off on his own to fight elsewhere, then he shows up with his kage cape and killed everyone with his teleporting daggers.