Law’s Marine Father and Grandfather.
Sengoku and Law seemed to have a docile relationship in Dressrosa. Since Law was a child Sengoku has been aware of him. Sengoku didn’t know Law by name at first, but if some kid pops up as the captain of the Heart Pirates using the Ope Ope No Mi. It doesn’t take Sherlock Holmes to figure out that Law is the child Rosinate sacrificed his life for. Sengoku saw Rosinate as a son, and Corazon paid that love and kindness forward to Law. It’s possible Sengoku could see Law as a grandson and carrying on the will of Rosinate. He could have been pulling strings to help Law out. When Law escaped he didn’t seem to be surprised. It’s almost like he expected it and or that he has been in a similar situation before.
Doflamingo may have became a Warlord, but Sengoku knows the true extent of Doffy’s wickedness. I’m sure he held a grudge against Doflamingo, thus wanted to see him taken down in the name of Justice, and for his personal satisfaction. Perhaps he knew Law wanted the same thing so he has been doing what he can to help Law take down Doflamingo.
Even the “Captain of SWORD” has reasons to want to see Doflamingo taken down. It would help him deal with Kaido, and his father could be avenged. Also he seems to be looking at Law’s picture on the newspaper.
The question is how much is Law invested in Sword? I’m not very inclined to believe that Law is an undercover Marine, however that would continue the trend of a Corazon being a double agent. Vergo was a Marine that was secretly a pirate and Rosinate was a pirate that was secretly a Marine. However it’s hard to believe that Law would become a Marine given what the World Government did to his family and hometown. I think if he could keep a safe distance as a pirate, he would be willing to join a sect of the marines that could align with his goals and values.
One thing to remember is that the Marines and the World Government aren’t exactly the same thing. Even Fleet Admiral Akainu opposes the World Government at times. Which if you remember Sengoku ordered Akainu to be a rebel marine during the battle at Marineford. And as many have point out he has a tattoo of a sword. Possible foreshadow?
BTW in the VIZ translations Marines are referred to as Navy.
Anyway lets talk about the most important person in Law’s life. Rosinate is someone that Law looks up to above all else. He named his pirate crew after him and even wore clothes in tribute to Cora. Given that the person he looks up to the most is someone that is a marine. It shouldn’t be too much of a stretch to think Law would be willing to work with marines that were as good of people as Cora.
Much like Drake he was an undercover agent. Was he apart of SWORD?
Even so Rosinate didn’t have blind faith in the Marines. He was willing to screw them over and steal the Ope Ope no mi for Law’s sake. So if you question the likelihood of Law trusting SWORD just remember, Law is someone that knows that despite how evil the World Government could be, there are good Marines that are even willing to rebel against the WG. Law may truly be a pirate but under the right circumstances is willing to work alongside SWORD. You could think of him as SWORD’s personal Shichibukai.
Notice how Rosinate seems to have an inherit suspicion and distrust of the WG. Also Notice how he makes a point to differentiate the Marines(Navy) from the World government.
Now that concludes the theory just talking about Law being apart of SWORD. For the most part it’s a safe theory. Nothing too crazy, cuz I mean most people already think that Law and Drake could be collaborating. And given that Koby is apart of SWORD, it’s safe to say SWORD are the good guys. So even if Law were to betray his alliance with Luffy he’d just be going from one group of heroes to another.
I believe Luffy is less concerned about whatever he can trust Law, and cares more about if Law is a genuinely good guy which he seems to be.
And really is that all that bad? What if Law being apart of SWORD mean he doesn’t want the One Piece and they won’t have to be enemies in the future. Well actually the exact opposite may be true. Law’s inclusion in SWORD and his desire for the One Piece might be connected.
*Theory by EliDZ