Luffy legit was about to Lose, he used his strongest new version of KKG.
Their is no reason to think that he skip a stronger version, in fact Luffy was attacking with the same attack twice, meaning that was his ulitmate move. He has nothing above it, otherwise he would used it against Kaido.
Sanjikun coping hard, even thought the size of KKG was the same, perfectly can see in the panels.
He can´t take it that Kaido easily endure a adv CoC+adv CoA KKG after he hyped it for years, saying it that it would be finiishing Kaido.
:holdthisl: