Yamato’s mother is Gloriosa. As an old lady she goes by “Elder Nyon”. Gloriosa said she had to leave the island because of the love sick illness and the only reason she survived is because she left.
Kaidou is a pretty evil and sinister dude. His wife isn’t gonna just be anybody. And the reason she would fall in love with Kaidou isn’t gonna be for his personality. But what is the main thing established about Kaidou? The main thing Oda has highlighted about Kaidou is his STRENGTH. The strongest creature, the strongest pirate, crew drawn to him due to his sheer strength.
Oda established that in Amazon Lily strength is beauty. The stronger a person is the more beautiful they are. This means Kaido is considered a handsome guy over there. Gloriosa is a former amazon empress. The empresses such as Hancock fall in love for simple shit. Kaidou beat Gloriosa in a fight and she fell in love with him because of his STRENGTH.
And now think about Yamato’s character. She is a strong woman like Boa, loves to fight, and cares more about fighting than femininity like Nami. This is basically the Amazonians. She is exactly like them. The amazonians are known for being strong women like Yamato. It’s clear Kaidou wanted a son. But that’s the thing, the amazon women can only have female children. They can’t have males.
Kaidou also has very hinted ties to Rusukaina. His name is hundred beast or king of the beasts Kaidou. When Luffy went to this island Rayleigh said there were 500 animals here stronger than him. Maybe Kaidou got this name by beating a hundred beasts on that island at a young age.
The reveal of Rusukaina is Chapter 597, an island where ONLY THE STRONG SURVIVE, an island of wild savage beasts. The reverse of 597 is 795. Just happens to be Kaidou’s intro chapter. Called hundred beast Kaidou or king of beasts Kaidou. This number is actually significant: 500. It just so happens this is the number that Law said in regards to the SMILEs. Kaidou have an army of over 500 artificial Devil Fruit users. The df chemical uses the dna of animals. What if Kaidou used the dna from these 500 beasts of Rusukaina to try and create the SMILEs?
Narrator says the WEAK LIVE THE STRONG DIE. Going back to this natural selection that Chapter 597 reinforced:
And a big point I believe Oda has used to hint the connection between Yamato and Gloriosa is the Vivre Card. Yamato was the one who told Ace how the Vivre Cards work. So the minute Ace card started to burn up she would have known he was in trouble.
But Kaidou doesn’t really teach Yamato that much. She likely learnt his attacks just copying him after losing so many times. So how did Yamato learn about this Vivre Card information? I strongly believe she learnt this information from her mother aka Gloriosa. And that’s her only vivid memory of her mother. And now think for a moment who was the one who told Luffy how the Vivre Cards work and that Ace was in danger? Yep it was Gloriosa.
Kaidou and Gloriosa are based on the story of the Enoshima dragon and the water maiden Benzaiten. The dragon terrorised a village and caused natural disasters and all sort. Very similar to Kaidou who has natural disaster like abilities. Benzaiten told the dragon to stop what he was doing and he fell in love with her. In some versions she rejects him and in others not but regardless there are extremely similar characteristics to Benzaiten and Gloriosa.
Benzaiten originated from an Indian goddess and Gloriosas, the flowers which Gloriosa was named after, grow in India too! Gloriosa superba is even Tamil Nadu’s national flower. It is also said to be a flower associated with suicide. Which just happens to be Kaidou’s favourite hobby. Maybe his reason for constantly commiting suicide has something to do with her.
It is also said the Benzaiten is always seen with a white snake. Accompanied by a white snake messenger. This just happens to be something that specifically Elder Nyon had with her. Funny enough Yamato uses an attack called white snake. An attack that is very different to any other attack she used. And this attack happens to be done in combination with Luffy’s Snakeman attack that seems to take inspiration from THE KUJA and Snake Princess.
Benzaiten is said to be from an island of ONLY WOMAN. Very strong evidence. She is said to be very wise and knowledgeable. Gloriosa told Luffy about the nature of the Vivre Card, she understood Luffy’s pure intentions while the other amazons didn’t see the bigger picture. She knew about Luffy’s actions taking down the Celestial Dragons.
And even just from a logical standpoint. We know Yamato is a beautiful character but she isn’t like Nami or Robin. She is a fighter, she loves to fight. And she likely felt insecure about being a woman. Since women are generally told to avoid violence and told to act feminine. She likely calls herself the son of Kaidou because of this. Yamato is very similar to the amazonians. Extremely strong for a woman and very naive about the outside world. Both Wano and Amazon Lily are isolated nations.
Also you can actually see a parallel between Kaidou and Gloriosa. When Kaidou met Gloriosa he was a nobody and she was an empress. During Wano arc, Kaidou is an emperor and she is a nobody.