Deva path alone can deafet Itachi. Deva path is extremely durable, he was punched by the six tails and smashed into the ground thrown against mountains and got up like nothing happend, extremely fast as seen when fighting six tails, and has shown water release, earth release, and fire release while fighting the six tails. And he has excellent taijutsu. Shoot he kicked the six tails in the face lol. All of that including the deva abilities I think he can take Itachi alone. Hecan counter everything itachi throws at him, and if anything he can use CT which itachi alone has no counter to and Chou shinra tensei. Many might say attack him during the five second interval but he is not defensless at that time and can still use other attacks and is still super fast. And besides when he uses shinra tensei in a one on one fight you have to realize that the opponent is struck and then the interval starts, so by the time the person is able to get back up from the attack the interval would be already done, being able to use it again. The same way he tossed around hinata he can do to anyone.
Oh and everyone saying itachi can destroy that CT, you guys forget that Pein stopped the six tails from attacking by putting him into a ball of rocks before sending him into CT.
Itachi will put up one hell of a fight and this will not be easy for deva but I think pain has the upper hand most of the time.
So personally I think deva can take out itachi alone.
Any thoughts and please no flaming.