In order for Blackbeard to become a Yonko, he had to defeat Wang Zhi, a former Rocks member. Luffy had to take out Kaido as well, and Buggy replaced Big Mom despite not having anything to do with her defeat. So how did Shanks get it?

Well, I think it was due to the defeat of Captain John. John was a former Rocks member. We can tell by the marines reaction that John was a great pirate in leagues with the Yonko.

I feel Shiki, Silver Axe, John and Wang Zhi were probably Yonko tier themselves but for some reason they never became Yonko. Shiki was the closest but his defeat to first Roger in Edd War and second to Garp at Marineford cost him.

Wang Zhi probably was content on Beehive island and was in a position where he stayed there and the marines never went after him due to the risk. Until the Rocky Port incident. Silver Axe probably went into hiding or something. But what happened to John?

We saw he was dead in Thriller Bark and was a killed by his own crew, now what i find odd is that his body is covered in bandages that existed before his fatal injuries. But if he was anywhere near Yonko tier, I can’t see his crew killing him. So for John to be killed by his crew feels off, however if he was already injured then maybe.

So this is what I’m thinking John was making moves 6 or 8 years ago and came into conflict with the Red Hair pirates. Shanks fought John and defeated him leaving him injured and gain enough credibility to become a Yonko. Maybe John was a Yonko or maybe back then there was only 3 so then Sanko.

Anyway John was known for his greed and cruelty so in his weakened state straight after a defeated his crew saw an opportunity and mutinied killing him for good and somehow Moria and Hogback got his body to make a zombie.

Well, a popular theory is Kid is the son of john. Kid is based off of William Kidd who was also a son of a pirate named John. Kid and John also share the same epithet: Captain. So what could Kid be John …..kid? His grandson? Either way it seems Kid has it out for Shanks and Buggy.

When Kid was arguing with Luffy about him becoming a Yonko while he didn’t he stopped and claimed that out of all of them the one that really gets under his skin is Buggy.

Now that is odd. From Kid’s perspective he knows Luffy, they both along with Law defeated emperors and yes, Kid and Law was 2 vs 1, but Luffy wasn’t fighting alone either he just more or less tagged in and out.

Anyway Kid by all means should be focusing his anger to Luffy. So why is Buggy becoming a yonko the one that has him the most annoyed, I mean Kid doesn’t know Buggy’s power is just for show and he’s been failing up this entire time, he should believe the hype.

Now the only thing I can think of that connects Kid and Buggy is their dislike of Shanks. Buggy hates Shanks because he startled him making him eat a devil fruit and drop a map into the sea, and because Shanks kind of just has this irritating personality where he doesn’t take Buggy seriously.

The only other thing that may connect them is Captain John. John may be a father or grandfather to Kid and Buggy is after John legendary treasure. Captain John was first mentioned when Buggy was randomly on some island with a skull digging for it. So if Kid is John’s kid perhaps they both had a run in looking for the treasure got into a fight and Buggy being Buggy got lucky and escaped leaving Kid frustrated and angry at the waste of time.

Now Kid crew up on an island in the South Blue that was not part of the World government and he crew up in poverty eventually leading his own gang and taking over the island to set up out to sea. Maybe he was close to John or maybe he hated John who was a cruel father and His dream was to go out to sea and prove himself as a better pirate than John kind of like Ace and Roger.

Kid actually shares some qualities with Ace, both are originally from the Aouth Blue and would have been the same age if Ace wasn’t carried for 20 months or was dead, both are not heads who can’t take a insult and resort to violence, both also bring out Luffy’s competitive side.

Ace grew up in Goa Kingdom, but he crew up in a bandit hideout and spent most of his time in the grey terminal or jungle. So while Ace never really became a gang leader himself he is connect to a gang life like Kid. Ace resented his father Roger and left to create a bigger legacy than his eventually he went after Whitebeard who was the closest to Roger‘s title, so if Ace beat Whitebeard then that would bring him closer to Roger’s legacy.

Similar Kid could have gone to sea in hopes of gaining enough power to eventually kill John however he received news that Shanks defeated him and in his weakened state his crew turned on him killing him.

Now Kid wants to fight Shanks as a means of proving he is the better pirate than John, and perhaps he believes Shanks has information on where John treasure is. He did tell Buggy he did but that was a lie….or was it?

Theory by MrBushido56 (https://www.reddit.com/user/MrBushido56)