Jiraiya: "Th... this Naruto is way too terrifying!"
Namikaze Minato: "Indeed. Although he is my son, he only saw the Nine-Tails release it once!"
Senju Tobirama: "What the Nine-Tails used was not a Rasengan at all. That guy's chakra is astonishing, but the Rasengan requires precise chakra control. That level of compression is far from being a Rasengan!"
Chapter 31