Board Thread:Theories and Speculation/@comment-25139119-20150807165411/@comment-5936871-20150809160420

The Manga, The Databooks, The Novels, and Gaiden all either state or prove that Naruto still retained his powers after the war. Both Naruto and Sasuke obtained the ability to use all basic nature transformations and yin-yang release when Hagoromo gave them their chakra (Databook stated this). Naruto specifically obtained the ability to bring people back from the verge of death and regrow missing organs, flight, and the ability to universally understand the nature of chakra and all things. Naruto still has SPSM, that was proven in Gaiden, and is indisputable. Now while Naruto hasn't added the beasts' power to the mode yet, him being able to undo IT after Sasuke said he had run out, on top of the Novels saying that he still has their chakra, should be proof that it regenerates. Also, if you wanna argue the canoncy of the novels. They may not be as canon as the Manga, but Kishimoto illustrated them, their authors are people he has worked with before, they're apart of the Naruto Project (Which has been nothing but canon excluding the obviously live-action play) and there was an official timeline chart revealed that placed them in the same canon timeline alongside The Last and Chapter 699 and 700. So even if Kishimoto didn't actually write them himself, saying they're non-canon because of that (Based on Wikipedia's definition of canon, when Animanga authors almost never use the term anyway), after them clearly being advertised to be canon is stupid.

If he used SPSM in The Last, he would have one-shotted Toneri and the movie would be over in seconds (he also clearly flew in The Last), and if he used all of the other beasts' power with SPSM in Gaiden, which he had absolutely no need to do against a single Shin clone or any of the Shins in general, he would have one-shotted them all. So using the whole "He hasn't used their powers since the war means he doesn't have it" isn't a good argument at all. Until it is factually stated or proven (Not by some he didn't use it when he could logic btw) that he lost the ability to use all of the other beasts' powers, he has them until proven otherwise.