Yeah, just what I was going to say. Sasuke will get beaten down, then the level 2 curse seal will appear at the end of 231. Then Naruto will be nearly dead and someone will probably interfere.

I think this new level of Kyubi-ness is probably around the same level as when he fought Haku. It looks like the teeth are huge and control is gone, only animal instinct remains. But I might be wrong, we shall see.