Akainu's past is clearly connected with Dragon's.
1) First of all, the fact that in Marineford Akainu himself had manifested an almost... fixation for Luffy as "Dragon's son", continuing to address him in this way, unique among all, for the entire saga:
A fixation that even led him to prefer him, Luffy, son of Dragon, over Ace, son of Roger, the fulcrum and objective of the entire Marineford War:
This detail tends to go unnoticed, but Akainu
preferred Luffy over Ace; Ace dies only because he is the one who gets in the way, thus saving Luffy.
2) This fixation of Akainu for Dragon has led many to raise an eyebrow and try to understand where the two, the marine and the man that even his subordinates seem not to know, could have met ... and the answer was: in the Navy.
Garp had repeatedly shown his desire to raise future Marines; among many:
Everything pointed to him having done the same with his son, Dragon. Well, five hundred chapters later this thing has finally been confirmed:
Dragon was actually a marine when he was young.
3) Now, given that Dragon was actually a marine and that Akainu seems to have a strange obsession for him, even in front of Roger's son (to whom, as mentioned, he "prefers" Dragon's son), when could this meeting have happened?
Well, it's soon said: the two, curiously, but not that much,
are the same age; 55 years old.
We know that Akainu joined the Navy 32 years ago, at the age of 23, and since Dragon is the same age, he could have done the same. This coincides with a Dragon who during the events of Ohara, 22 years ago, was no longer part of the Navy. But this does not create any problem, having hypothetically joined at least ten years before those events.
4) The similarities do not end here:
- not only are the two of them the same age;
- not only are they, as seen, somehow both connected to the events of Ohara, but;
- with the post-TS they have assumed similar positions: both are at the head of their respective organizations, Akainu of the Navy and Dragon of the Revolutionaries;
- now that we have discovered that Akainu's bounty is 5 billion, we can also draw a parallel with that of Dragon who, as he was known as the "worst criminal in the world" when BB was still alive, should also have a bounty of at least 5 billion:
- there is another potential parallel that I would like to draw attention to:
both seem to be placed in fierce opposition to one of the "legends" of the OP world, original or "reborn":
Akainu is in opposition to Luffy, the new Joy Boy, whose brother he killed and to whom, in trying to kill him, he procured a huge scar on the chest in a manga where scars bind the destinies of the characters:
Dragon, instead, he is clearly placed in a relationship of radical opposition to Imu, his goal being the fall of the World Government and the Celestial Dragons in particular and Imu being the first and darkest foundation, as well as the true leader, of the GM and true "King" of the Celestial Dragons:
To recap:
1. Akainu showed MF an unusual and even excessive obsession with Dragon;
2. we had confirmation that Dragon and Akainu were both in the Navy;
3. Dragon and Akainu are the same age, which in addition to being one of those little connection indices that Oda likes, like heights, makes it even more likely that they served together and therefore met;
4. they are both linked to Ohara: one as an integral part of the events, one instead as the place that led him to decide to definitively fight the WG;
5. they both have the "same" position: leaders of their respective forces;
6. they probably have a very similar size, in both cases at the level of 5 billion;
7. They both appear to be in an oppositional relationship with the "legends" of the OP world: Akainu with Joy Boy (reborn); Dragon with Imu, King of the world and supreme leader of the Dragons.