lol, interesting... KOing Kaido has been done before, 7 times already. Even if this is real KO like those 7 times before.
Nothing new, nothing impressive especially considering that Kaido was exhausted after a gauntlet vs 15 people and several Luffy rounds.
The damage from this punch is so low that it cant even scratch Kaido's scales... Only 2 attacks have managed to do that.
And why are you ranking a simple punch like this above Hakai from two Emperors?