Here’s a theory on why I believe Dragon and Akainu have some sort of history with each other, where they were possibly friends/comrades or enemies at some point in time.

I noticed something interesting, Akainu calls Luffy not by his name, but rather “Dragons son” multiple times throughout the war, as if he knew Dragon personally. Akainu’s unusual animosity towards Luffy, which no other marine has shown during marineford, implies something deeper.

Akainu knew that Luffy was Dragon’s son before Sengoku announce it at marineford. Not very many people know too much about him or that he even had a kid specifically, which is surprising that Akainu already knew about this information.

Garp always wanted his grandchild (Luffy) to always become a marine like himself, but what about his son? I’m sure Garp wanted the same thing for Dragon and I believe he did for a short period of time.

I believe during sometime Dragon was a marine before he started the Revolutionary army that was created 19-24 years ago in between Roger’s death and Luffy’s birth. Akainu joined the marines 32 years ago, within that 8-13 year gap I think Akainu and him were comrades or enemies.

Just like Garp, Dragon despises the celestial dragons and even declared war against them. I believe in the past something personal happened to Dragon made him revolt against the WG, possibly the death of his wife. This may be one of the reasons he seeks out revenge against them.

I also believe the meaning behind Dragon’s tattoos must have something to do with Luffy’s mom because he got them in between Rogers execution and Luffy’s birth. I expect to see Akainu interacting with him in his flashback. They also coincidently are the same age, 55 years old.

I truly believe that these characters are connected and have history together. When Oda shows either of their flashback, it’s bound to show them together or interacting with one another. The day these two see each other face to face will be legendary.