It was always curious to me that Oda chose to name Akainu, Sakazuki, which means Sake Cup.
In One Piece, sake represents brotherhood/bonds, ones as strong as family. Luffy shared a sake cup with Ace and Sabo to cement their brotherhood, and the grand fleet did the same to establish themselves, calling it “son’s cups”, and then there’s Binks Sake which is full of meanings that tie into it.
So why would Oda name the one person who took away Luffy’s brother after something that symbolizes brotherhood? I think that’s where we can read into his backstory.
I think Akainu had brothers of his own, his Ace and Sabo, who were killed by pirates when he was a child. I think once we get to his backstory, we’re going to see what would path Luffy could have taken, basically having Akainu serve as an inverted parallel of Luffy.
When Sabo “died” as a child, Luffy was only able to overcome it thanks to Ace. What would have happened if Ace had died that very day leaving Luffy alone in the world? I think Akainu is the result. He turned his anger towards not only pirates, but the whole concept of brotherhood/bonds/nakama itself.
There are plenty of theories going around of how the One Piece will ultimately result in the entire world coming together as one, either metaphorically by sharing Binks Sake, or literally by destroying the Red Line and bringing the seas together or some combination of both.
I think if that ends up being the case, Akainu would be a really poignant obstacle, someone who’s going to refuse the idea of brotherhood because he himself views it as a lie, because to him, evil can’t be overcome by people coming together, it can only be overcome by being willing to sacrifice anything to defeat what is defined as “evil”, and Luffy and likely Sabo will have to show him how strong a bond of brotherhood can be.
Theory by Ocean Man (https://www.reddit.com/user/Clean_Strategy_9533)