You already know what i think on this so i will address the other options.
Luffy aint killing him. I dont think that needs expanding on its just not something he does.
For people say zoro killing kaido is bad because it would take spotlight away from luffy kidd or law doing it would be much worse to luffys rep in comparison. Of course this would be even if they had the beans to do it which they dont.
This is something ive seen a lot. Big mom betraying kaido these were my thoughts on that before 1002
After seeing the way she not only took killer out before he could attack again but then reacted to zoro attacking him i feel more than vindicated in my beliefs on this topic.
Now this is an interesting one. Back in the day i thought this was the only other viable option. But events since 956 changed my mind on this or the marines coming at the end.
First of all blackbeard in 956 moved out to take something before the marines do so a clash between the two parties is inevitable. I dont see either coming to wano to take kaido out for a few reasons. First the arc needs to end with the feast luffy said and wano opening the borders.
Bb wont come to wano to kill kaido take his fruit then leave a) luffy alone or b) the road ponlyglyphs and would try sink wano.
Same with the marines they wouldn't come to take kaido away and wave off luffy and wish him a nice day.
On the capture front it has failed 18 times to restrain this man. 18. Add this to the ridiculous recovery this man has they cannot contain him. Why would it be different ?
@Garp the Fist made a thread just how much the idea of not just death but beheading kaido has been pushed so far in wano. All the ingredients to match ryumas legend are slowly falling in place
It has all the build up now its just about (excuse my pun) the execution.