Board Thread:Theories and Speculation/@comment-26403664-20160206050741/@comment-26403664-20160206165027

I doubt it had anything to do with Kurama at all. The reason why Naruto's and Minato's chakra modes look the way they do is because of their special ability to mix and transmit chakra so well, and I think that is because of something passed down from Ashura. Any normal person as a jinchurriki of Kurama would have just gone into the flesh and bones verion of Tailed Beast mode.