I love the fact that Kaidou and Luffy still speech like if it wasn't a fight "hey, i'm not in rubber like you!".
Looks like he is kinda intrigued by Luffy awakening completely crazy and you can see he's asking himself questions.
Kaidou is not fighting trashy neither. Psychologically it's a bit "melted" in his head, + the fact that he was kinda pissed about how it ended with the CP-0 intervention.
Looks like he wants to fight to understand what's going on. And understand Luffy.
Looks like we got a change in the character, he saw everything in his pirate's life…
But nothing like this. Fighting an old comic book character.
The power totally fits with Luffy personality and fighting style since the beginning, when their opponent say "fight seriously!" "But that's the way i fight! I'm serious!".
It's the pinnacle of what Luffy is, probably influed from the start by the DF (perhaps the Myth/Nika etc. came after, but i really believe that the max power of him would have been planned to be... Like this. Cartoony)