Board Thread:Theories and Speculation/@comment-25093611-20160221130833/@comment-9782468-20160222191513

And Naruto randomly started making gigantic Rasenshurikens didn't take up too much chakra even when he could barely use three per Sage Mode before, even without a cloak.

It's not the Avatar/Susanoo, it's just that their reserves grew to allow them to scale their techniques up