I doubt that Oda will ever show any protagonists kill anyone.
If Kaido’s head gonna be choped off it will be by an antagonists (Marines, CP-0 or an other emperors).
If Kaido’s head gonna be choped off it will be by an antagonists (Marines, CP-0 or an other emperors).
Luffy showed killing Akainu wouldn't even make sense for example. It would lower the character to Akainu's standards after all. He could end up jailed for life or have a peculiar sort of punishment.
Like Zoro might also not kill Shiryu honestly.