One person was called JoyBoy but that may be a title and not the name of the person. Like Gol D Roger was Pirate King, Pirate King was a title not his name.
Kaido killed Luffy anyway so he was kind of right to believe in that. But turns out Luffy is being possessed by JoyBoy himself.
The only attack that made scar on Kaido was coated with CoC then is pretty safe to assume Asura was coated with CoC too. If Kaido fought other people who knows CoC coating and even use blades then Zoro AP thrash them all for scarring Kaido without ACoC and now with ACoC he will one-shot kill easily.
Chose your option.
Whether it's a title or a name is Irrelevant...
Whoever that person was that was called joyboy was said to have his will inherrited by someone in this specific time. rogers crew found that out.
This was OBVIOUSLY luffy...and like I said this has been known for YEARS.
not being able to hear someones voice through COO is not the same as dying otherwise everyone on skypeia would still be dead. including most strawhats
Luffy is not dead and never died.
and I seriously doubt Joyboy is possesing luffy lol
no it's not safe to ASSUME anything that's just you're zorofanboy headcannon lol. there was NO indication(black streaks) that Zoro was using advCOC coating in his asura attack vs kaido. Kaido only said he awakened basic COC at that time.