Hello guys,Siranime here!Some of you of course would remeber my previous thread regarding the 7th Warlord.This thread however,unlike the previous one would be more theory than wild speculation.One thing I've got to mention is that this theory is entirely my ceation.So if you'ce seen similar theories,it means that others have arrived to the same conclusion as me.So let's begin!
First of all,I'd like to point out that half of the Yonko of the previous generation seem to somehow be related to the four Mythical Beasts of the Far East.Those beasts are the Seiryu(Azure Dragon),Suzaku(Vermilion Phoenix),Byakko(White Tiger) and Genbu(the Black Tortoise).
So you might ask how could this be related to the Yonko?
Firstly,someone has Phoenix powers AND is related to one of the Yonko.It's this guy
While he is mostly blue,if I'm not mistaken the yellow part is more VERMILLION in the manga.He is the first mate of a previous generation Yonko-of Whitebeard!While many people do not know it,the Suzaku also represents a cardinal direction-South.HEnce I believe that Whitebeard,Marco come from the SOUTH BLUE(or at least that's where the crew was initially formed).
2nd:Genbu,the black tortoise.
So is there actually a CONFIRMED Yonko member that has a Zoan and can transform into a Black Tortoise?The answer is yes and it is this guy:
Moreover,you should notice that it is not exactly entirely black,similarly to how Marco is not entirely Vermillion.He is a crewmember of Big Mom.The Black Tortoise represents a cardinal direction as well forever:North.Hence I believe that Big Mom's crew comes from the North Blue.
But what about Shanks?
If you remember the meeting between Shanks and Whitebeard,Shanks mentioned that he comes from the West Blue.
^Something that the Wikia confirms in the Shanks page,on the "History"part.
So what is the beast that signifies the direction of west?That would be Byakko,the White tiger.
But who would have the White Tiger Mytical Zoan in Shanks's crew?I believe this guy:
Also check this out:
Barely on the far right you can see someone with feline characteristics.I believe that is Rickstar in his Hybrid Zoan form!Don't forget that he's a Rookie.He has a 94,000,000 Berries bounty.He was made fun of both Shanks and Whitebeard.He could rely heavily on his Devil Fruit and he may actually be the only Devil Fruit user in Shanks's crew.
Last but not least-Seiryu the Blue Dragon that can control the weather and represents the East.According to the logic so far,the older Yonko have a crewmember with those Zoan powers.The only one remaining is Kaido.Hence I predict that someone in Kaido's crew has the Seiryu Devil Fruit.And that Kaido actually comes from the EAST BLUE!
KAIDO
According to this theory he comes from the East Blue.But wouldn't a weather controlling Dragon Devil Fruit be in his possession,since it sounds ridiculously powerful?I don't believe so and here is my evidence:
*The Yonko captains so far were not the ones who had those Mythical Beasts Devil Fruits.It was a crewmember.Hence a crewmember would have the Dragon fruit.I believe it will be the first mate adn,ultimately,Zoro's opponent.
-Zoro has been depicted as a Dragon in various media.
-"Santoryu" has"Ryu" inside it,which can mean DRAGON.
-Tatsu Maki translates to Dragon Twister.
-He defeated Ryuma(Pay attention,the "Ryu" pops up again),who killed a dragon!
-He killed the artificial dragon in Punk Hazard.
-Hence Zoro would fight that Dragon Fruit user.
But what would Kaido's fruit be?Two possibilities:
What animal is refered to as "King of the beasts" in our world's tradition?THE LION.
I beliece that Kaido has a lion Devil fruit.It can be an ordinary lion,a mythical lion(like the Nemean lion that had an impenetrable armor fur)or a beast that is part lion(Chimaera or some other creature for example).Also there are bound to be many divine lions in our world's tradition or to some religion.
-It doesn't have to be an incredibly powerful or a mythical Zoan however.Kaido is refered to as"The strongest creature in the World",not "He who has the most powerful Zoan".Remember that the future Pirate King is the user of the Gomu-Gomu,which is definitely not the most powerful Paramecia.
-The lion Fruit would also represent Kaido as the leader.He the leader-king and his army of animals(The Smile users).
2nd possibility:An animal that has to do with cold.
Since the Winter island that X Drake landed on is a personal favourite of his(I believe the Lion one,but this one is good to be mentiones as well).
Let's return to the "Kaido comes from the East Blue" part.It would actually make sense in various ways:
-A current Yonko that belongs to a previous generation of pirates THAT COMES FROM EAST BLUE VS a rising legend of the new generation THAT COMES FROM EAST BLUE(Luffy).
-The "generation theme is important:
More obvious to the anime,where Crocodile clearly says"You're just a rookie pirate that has come out of nowhere.Do you know who I am"He was a member of a previous generation of piracy,a well-known one too and a Warlord.
*Also remeber that Big Mom said:
Middle panel.Kaido would be largely unaware of Luffy,similarly to how Big Mom was.In the anime the line goes"I remember your name NOW.'
What about his background?
So what is a place in East Blue that's an animal paradise or where starnge and quirky animals live.Yes it is this place:
*So where am I getting at?I believe that is Kaido's HOME ISLAND!He somehow attained high intelligence and left the island to become a pirate.Sounds strange?The series we love is full of strange!It is the only trully strange place in East Blue and would be fitting for Kaido's background.Plus that way everything is connected together and we know that Oda loves Call backs and Foreshadowings.
*Kaido could quite possibly not be an animal at all.Yeah I know that he has been reffered to as "The Strongest Creature alive".But what if that refers to the fact that he's the strongest Zoan,instead of the strongest animal per se?He doesn't necessarily have the strongest Zoan,but he's the best Zoan user.What if he's a human?What if he's the CAPTAIN OF GAIMON'S CREW?Or the pirate that took the treasure from the chests Gaimon has been guarding for so many years all alone,the chests up the hill that were empty,before Gaimon's crew arrived?Think about those possibilities.
Don't forget to mention your opinion about all these.
P.S. I accidentally wrote "Yonkos" on the title instead of "Yonko".Please don't be too harsh about it!
P.S.2 
To me he looks more human than animal.
But on other hand Shanks in now Yonko and he is at Zenith of pirates among 4 strongest of them and he cant let himself have any handicaps.