Originally Posted by Pritha
I dont remember but it was once said that the seal by minato on naruto was designed in such a way that a bit of kyubi's chakra to mix with naruto's
What i am guessing is now he has gotten used to kurama's chakra so much that it strting to mingle with his and hence the strange effect. Unlike them being separate (maybe)
actually I think the blend of their chakra has already taken place. I wonder why Orochimaru and comp was able to perceive it as Naruto's chakra rather than that of the Kyuubi.