I was thinking about one thing today: what if sasuke sealed the bijuu's just to test his strength with naruto. From what i know, kishi is a fan of dragon ball. think of the analogy this way: when they fought majin buu, Vegeta deliberately fell under babidi's spell, in order to get stronger and fight Goku. Maybe sasuke did this to seal the bijuu's and to test his Rinnegan with Naruto's strength. So, what do you think?