What is the Moon Rabbit?
In ancient Chinese mythology the Moon Rabbit also known as the “Jade Rabbit” is someone who makes the Elixir of life for the gods.
The Legend is that eventhough it makes the Elixir for the gods even mortals can obtain it. The objective is to please the Rabbit but the challenge is to win it over so if the Rabbit decides you will get the Elixir you’d become immortal.
It could be possible that the Moon Rabbit could exist as a Mythical Zoan devil fruit.
Possibility of Mythical Zoan : Moon Rabbit
Kaido’s love for Zoan users among his crew. He could have obtained this devil fruit and given it to one of his trusted Nakama.
It’s unknown about its physical powers but it could be similar to the powers of Princess Mansherry
Princess Mansherry ate the Paramecia Type Heal-Heal fruit (Chiyu Chiyu no Mi) but she’s able to create tears that can instantaneously heal anyone so the Moon Rabbit could give the ability to be immortal but I think there is a limit to the time where Kaido could be immortal and the Moon Rabbit can only create the immortality elixir during a certain event and it will last until the next event.
The one who ate the Mythical Zoan Moon Rabbit should be able to create the Elixir using another similar method but the Elixir of life can only be done on rare occasions.
How does the Elixir work?
I think the immortality effects are actually temporary but unlike Big Mom’s ability to get thinner and weaker after she hasn’t eaten for some time, Kaido’s physical strength , stamina or durability won’t be effected with or without the Elixir, when he’s immortal it just ensures his ability to not die but if Luffy or anyone takes the producer Kaido will not lose any of his physical abilities.
Kaido’s Suicide Hobby
So Kaido also tries to commit suicide but always end up unsuccessful it but I think this is what he does just to pass the time and testing whether he would die with immortality or not.
His durability could mostly be due to Haki tho making his body just like Big Mom’s.
How will this help Luffy and the Alliance to beat Kaido
So like I said before Kaido’s immortality will last until the next event that the Moon Rabbit can make the Elixir and this might given to his opponents a window of opportunity to capture the Moon Rabbit user whether he/she is a Nakama or a prisoner meaning that Kaido can’t become immortal giving them a chance to fight him! I doubt that Luffy and Law can do it alone since Kaido’s powers are just the same but that’s a theory for another day…
*Theory by King of beasts kaido