The kage bushin training couldve helped him in his battle over control. Now im not saying the kyuubi has been beaten but it could be that naruto has become more tolerant of the kyubi chakra or has subconsiously learned a new way to utilize it.
Ok well.. consider these..
1. Naruto said he will save sasuke with his power and never ask for help from the fox again after he hurt Sakura..
2. when he training, a bunch of clones turned into the fox, Yamato supressed it. but this kept going on. So imagine that since that kept going on, the Kyubi traits were still in the clones, which return to naruto when they go away, and when ever he uses the clones, the traits on the nine tails return.
3. The Fox is trying to come out, but naruto is denying him the right to open that cage.
4. The seal the 4Th put on him wasn't so he can become one with the fox, It was to help naruto progress and enable some of the fox's chakra to come out when he is in danger. Yes the seal is weaking, but who knows, that could've been then intention of the seal from the start.
I think that the stronger Naruto gets by himself, the more the demon wants to come out.
does the sharingan really matter?
i mean when you get stronger and faster shouldn't your eyes/ senses develop so you can see your own motions?
or is sharingan like an extra boost up from your normal eyesight so you can see the movements 3-4 times stronger than you?
any way id love to see sauske try and copy solar flare *opens eyes wide to see whats going to happen and gets blinded* (sad dbz refrece)