As I've stated numerous times, (I believe this is 6 this week, so clearly you must either be absent or blind) it's not the power borrowing that bothers me, it's the 100% separate consciousnesses coalesced into one body that can act entirely independent of each other and can support each other without the acknowledgement or even awareness of the other.
If Naruto had thought, "Shit, amaterasu, I need a chakra cloak" then activated one, that would be 100% kosher in my book. But he had no counter. He knew he didn't have a counter, and he never attempted to use a counter, he got lucky that Kurama had a counter and knew when to use it.
I think you have not learned anything from Naruto all this time. There is no 2 vs 1 in this fight. Naruto is not taking order from Kurama. Inside naruto, Kurama does not see anything outside, and he does not hear anything from outside. You need to understand that at any time,
only one of Naruto or Kurama is acting. In fact, the Kurama you saw during the fact was a chakra cloak. All the Bushin you saw were Naruto's bushin in kurama cloak. They have Naruto's mind, not Kurama's.
When Naruto need chakra, rather than forcing Kurama like Sasuke did, he ask kurama to give him chakra. So, you mistaken to think Kurama is fighting against Sasuke. All Kuaram does is to give chakra to Naruto when Naruto ask for it. If Naruto want a Bijudama, he use Kurama's cloak to create the Bijudama.
Simply put, Kurama is a mere chakra store for Naruto.
In case you don't understand it yet, go back on Obito vs kakashi's team. Then, you will see that in order for the Biju to do anything with the outside world, he need to switch with the Jinchuriki for controlling the body of the Jinchuriki.
My opinion about this is that Sasuketards have never understood the concepts used in the series. You don't even understand what Jinchuriki really means and you don't know that the cloak naruto use is a merging of Naruto's chakra with Kyuubi's chakra. The real Kyuubi is sitting peacefully inside Naruto, and every time he show his ass outside, he got soloed by Madara or Sasuke. He has zero intelligence, zero battle strategy, and a hopeless being that knew only hatred.
Thus, the way Naruto uses Kyuubi is exactly the same way Sasuke uses the chakra of the Bijus. Naruto creates a cloak that look like Kyuubi, and Killer Bee trained him to do so. Naruto could have created an eagle with the chakra or so.
