Board Thread:Naruto Discussions/@comment-24168857-20141020124144/@comment-25382671-20141020175004

Madara was playing with Guy to see his full strenght. At this point, I think that was just Kishi trying to show us Guy's true potential before the closure of the series.

In my opinion, Kakashi with both Mangekyou would win against Guy with the Eight Gates opened.

Against Seven Gates, Kakashi with Sharingan would also win.

Now, if it is Kakashi without Sharingan, I believe that he could beat a Six-Gate Guy using his Five-Gate release seal. (I seem to remember him mentioning that he could go so far as that, correct me if I'm wrong).

Other than that, I don't know, nor do I care to wonder. :P

Edit: Corrections made.