I'm going to use this thread just to show Kaido's CoO here.
He was easily able to "hear the voices" of the members on the roof after the Hakai, something Big Mom couldn't even though everything was covered in dust.
Even without making use of the FS he still managed to defend himself against some blows from Luffy's Snack man that are characterized by being very fast.
With Kaidou deciding to make use of his FS overcoming all of Luffy's blow and blitzing him in the process.
Kaidou's CoO has the all-encompassing ability and scope of knowing everything that's going on in Onigashima with him knowing what happened to Big Mom while Luffy doesn't, Luffy only came to question whether Kid and Law had defeated Big Mom after Kaidou told him.
Another evidence of Kaidou's CoO being able to easily identify what goes on inside the castle and across the island is the speed with which he found Momonosuke.
Kaidou's FS surpasses Luffy's FS and in general Kaidou's CoO still has better characteristics compared to Luffy's CoO such as the ability to sense the presence of individuals even far away as was the case here and even "voices"...
In general, Kaidou has the 3 characteristics:
- Feel the voices
- Feel the presences.
- See the future.
While Luffy's, although he has the ability to see the future, he failed in the aspect of sensing long-distance presences as was the case here with Kaidou who managed to see that Linlin lost even though he was outside Onigashima.