All throughout the War Arc, Kurama and Naruto have had their chakra run dry leading to Kurama fetching more. Why is it that Kurama conveniently failed to produce chakra during Naruto & Sasuke's brawl despite it lasting like 10 hours? All Naruto really needed to win was the kn0 cloak, which could recover a whole lung, and the kn0 cloak is like 0.001% of Kurama's chakra.