Obito + Juubi = Jubitothe **** is a jubito
I don't think he'll be stronger than rikudouJubito is going to be the most powerful character in all of Naruto. You watch and wait. I wonder if in the end he is going to admit he was wrong and become apart of Naruto's Ninja way as well. Like all of the past villains.
http://naruto.wikia.com/wiki/SenjutsuYay, a "gattai" moment incoming.
Also, what is this senjutsu stuff
I believe Jiraiya said at some point during the series, that summons could only last for a certain amount of time in the human land before they have to return to their homeland (I say land because they're not in another planet nor dimension).I thought it was revealed that summons could only last for a certain amount of time when Jiraiya was teaching Naruto the ability. Either that, or I'm really good at assuming things.