I think the biggest takeaway that people who are upset at Kaido's portrayal in the last several chapters are not considering is the Scabbard's sudden use of Ryuo and their ability to inflict damage to Kaido. This is the second time that we are getting Kaido's thoughts on what is happening to him in real time, even he himself is confused which hints towards that what the Scabbard's are currently doing is unsustainable/one time event.
I do not know what Oda is currently setting up but it wouldn't be out of left field in my opinion for it to be revealed that under certain dire circumstances like this one, where the resolve of the Scabbards is so strong, that they are willing to literally die before they strike down Kaido that Ryuo could possibly be temporarily inherited. (Perhaps Oden's reference to his "soul living on" in this panel has an additional meaning to just his will being passed on to his followers and children.)
I don't know exactly, but I'm spitballing here for possible reasons because of Kaido's dual internal monologues. Kaido's been around the block, it is very clear to me that Oda demonstrating twice that Kaido being damaged and being confused about it is abnormal.
i have been thinking about kaido's inner thoughts as well.
ryuo means you inflict damage to the users body from the inside to outside, and one can achieve that due to their haki (and maybe haki sorrounding them?) directly flowing through their own body into the enemies body, right?
from that i kinda get the vibe that kaido is kinda "letting" it happen because he still has alot of respect towards oden (oden lives on in HIS mind as well)
it makes it easier for the scabbards with their clear goal to avenge oden (thinking and being driving by him) to get that flow of haki going - especially because they are doing this as a group!
and btw it is still a 9 vs. 1 fight, sure kaido should have "some" trouble, he can't be the beast that deflects everything with ease
dunno why some people expect him to be like that. i at least don't want him to be invincible at all, i really enjoyed the fight so far.
this makes oden's sacrifice worth more or understandable, because he trusted his vassals. that trust is pushing them to their limits now.