So here is the thing... I have seen a lot of people complain that Kaido wants to fight strong opponents and wants to die... yet never does anything. He does attempt to attack Whitebeard, but that was in a fit of drunken range.
So why this contradiction? Why does this drunken, suicidal, extremely violent maniac who apparently wants to die a glorious death... never does anything? Doesn't appear to make sense.
Except, when you think about it... it actually does.
Look at Kaido's actions throughout the story. He takes over Wano, which is basically an impenetrable fortress that even the World Government's couldn't easily infiltrate, and forces the population to work in weapons factories. Kaido then uses these weapons - both for his own forces, and selling them... but that is set back by Mr. Pink Flamenco's defeat. It is clear however that he is building up a massive army. Kaido also makes an alliance with Big Mom,
Now, if Kaido's true goal really was to simply fight strong opponents and die, he could have easily just charged in like a lunatic, kinda like Whitebeard did but without Whitebeard's justification, and .
But, and here we come to the headcanon/theorycrafting part: I don't think that was really Kaido's goal.
Kaido was a member of Rocks pirates. Rocks, who knew the true nature of the World Government. Rocks, who had met Imu himself. Rocks, who had went and searched for a specific devil fruit to try and kill Imu personally.
Remember what King mentioned? He knew about the Joyboy. And Kaido himself spent time searching for the Joyboy, at least if I am reading his "It seems you are not the Joyboy either" line correctly.
So what I believe is going on is, Kaido knew not only about Imu but also about the necessary conditions for Imu's defeat. He is well aware of the strength of not only the Navy - which alone would have been able to overwhelm the Kaido - Big Mom alliance - but the World Government as a whole, including its secret forces.
Big Mom knows as well. That is likely part of the reason why she sought the alliance with the giants.
Now back to Kaido... yes, Kaido wants to die. But I believe that he wants to die in a way that will matter - and matter in the large picture. He wants to leave a legacy, like Whitebeard's but more impressive.
Simply put, Kaido wants to draw out World Government's secret forces. He does not want to do as Whitebeard did, fight the Navy and die doing that - because to be frank, Luffy awakening his Conqueror's Haki and Whitebeard's dying proclamation reaffirming the existence of One Piece and thus the Great Age of Pirates - these were the only events that caused any true damage to the Navy, let alone World Government as a whole. None of the Admirals were seriously injured in the war, and Aokiji leaving was caused by Sengoku's retirement, not by the Paramount War.
For Kaido, such a death would be irrelevant. Whitebeard already did everything that could have been done in such a situation, as Kaido himself laments. And what Whitebeard did, Kaido could never match even if he somehow recreated the exact conditions - he is a reigning Yonkou, a powerful pirate, but he is not a legend of the old era like Whitebeard is. Anything he said would not have weight enough to make a major impact on the world. Kaido suiciding against Marineford would be seen as nothing but an inferior Whitebeard cosplay, a Whitebeard-lite wannabe dying in a pathetic attempt to emulate Whitebeard's glory.
Kaido does not want that.
So instead, Kaido's goal is to find and fight Imu himself. But to do that, he has obstacles to overcome. He needs enough forces and weapons to overwhelm the Marines, the CP0 and the Holy Knights. He needs to find out how to kill Imu.
And to do that, he needs to prepare. If Whitebeard was unable to do defeat just the Marines, and was in fact overwhelmed by them, it is clear Kaido - a much weaker pirate overall even if he may have been stronger 1v1 than Oldbeard - would stand no chance of achieving his goal. So he needs to build up his forces. He needs a secure base operations - so he takes over Wano, a country nearly impossible to invade. He needs stronger army - so he starts producing and selling weapons, producing artificial Devil Fruits, and starting conflicts all over the world - weakening the World Government while at the same time strenghtening his own forces. And his alliance with the Big Mom would not only strenghten his forces, but also provided him with (however tentative) ties to Elbaf, a country he has good reasons to believe would hold the key to Imu's defeat.
And all of this is also likely the cause of his drinking, his depression and mood swings.
Pity that it is so badly explained though, that most of the above is basically headcanon. But headcan(n)on or not, I do believe that was the idea behind Kaido. Just - very badly explained.
Or at least, so I hope.
So why this contradiction? Why does this drunken, suicidal, extremely violent maniac who apparently wants to die a glorious death... never does anything? Doesn't appear to make sense.
Except, when you think about it... it actually does.
Look at Kaido's actions throughout the story. He takes over Wano, which is basically an impenetrable fortress that even the World Government's couldn't easily infiltrate, and forces the population to work in weapons factories. Kaido then uses these weapons - both for his own forces, and selling them... but that is set back by Mr. Pink Flamenco's defeat. It is clear however that he is building up a massive army. Kaido also makes an alliance with Big Mom,
Now, if Kaido's true goal really was to simply fight strong opponents and die, he could have easily just charged in like a lunatic, kinda like Whitebeard did but without Whitebeard's justification, and .
But, and here we come to the headcanon/theorycrafting part: I don't think that was really Kaido's goal.
Kaido was a member of Rocks pirates. Rocks, who knew the true nature of the World Government. Rocks, who had met Imu himself. Rocks, who had went and searched for a specific devil fruit to try and kill Imu personally.
Remember what King mentioned? He knew about the Joyboy. And Kaido himself spent time searching for the Joyboy, at least if I am reading his "It seems you are not the Joyboy either" line correctly.
So what I believe is going on is, Kaido knew not only about Imu but also about the necessary conditions for Imu's defeat. He is well aware of the strength of not only the Navy - which alone would have been able to overwhelm the Kaido - Big Mom alliance - but the World Government as a whole, including its secret forces.
Big Mom knows as well. That is likely part of the reason why she sought the alliance with the giants.
Now back to Kaido... yes, Kaido wants to die. But I believe that he wants to die in a way that will matter - and matter in the large picture. He wants to leave a legacy, like Whitebeard's but more impressive.
Simply put, Kaido wants to draw out World Government's secret forces. He does not want to do as Whitebeard did, fight the Navy and die doing that - because to be frank, Luffy awakening his Conqueror's Haki and Whitebeard's dying proclamation reaffirming the existence of One Piece and thus the Great Age of Pirates - these were the only events that caused any true damage to the Navy, let alone World Government as a whole. None of the Admirals were seriously injured in the war, and Aokiji leaving was caused by Sengoku's retirement, not by the Paramount War.
For Kaido, such a death would be irrelevant. Whitebeard already did everything that could have been done in such a situation, as Kaido himself laments. And what Whitebeard did, Kaido could never match even if he somehow recreated the exact conditions - he is a reigning Yonkou, a powerful pirate, but he is not a legend of the old era like Whitebeard is. Anything he said would not have weight enough to make a major impact on the world. Kaido suiciding against Marineford would be seen as nothing but an inferior Whitebeard cosplay, a Whitebeard-lite wannabe dying in a pathetic attempt to emulate Whitebeard's glory.
Kaido does not want that.
So instead, Kaido's goal is to find and fight Imu himself. But to do that, he has obstacles to overcome. He needs enough forces and weapons to overwhelm the Marines, the CP0 and the Holy Knights. He needs to find out how to kill Imu.
And to do that, he needs to prepare. If Whitebeard was unable to do defeat just the Marines, and was in fact overwhelmed by them, it is clear Kaido - a much weaker pirate overall even if he may have been stronger 1v1 than Oldbeard - would stand no chance of achieving his goal. So he needs to build up his forces. He needs a secure base operations - so he takes over Wano, a country nearly impossible to invade. He needs stronger army - so he starts producing and selling weapons, producing artificial Devil Fruits, and starting conflicts all over the world - weakening the World Government while at the same time strenghtening his own forces. And his alliance with the Big Mom would not only strenghten his forces, but also provided him with (however tentative) ties to Elbaf, a country he has good reasons to believe would hold the key to Imu's defeat.
And all of this is also likely the cause of his drinking, his depression and mood swings.
Pity that it is so badly explained though, that most of the above is basically headcanon. But headcan(n)on or not, I do believe that was the idea behind Kaido. Just - very badly explained.
Or at least, so I hope.