I believe X Drake, who is believed to have left the military to become a pirate, is actually a deep cover agent much like Rosinante was for Sengoku.
I’ll start from the beginning. In chapter 767, when Doflamingo uses the bird cage on Diez Barrels pirate crew in order to get the Ope Ope No Mi, one character escapes, “Dorry” who is later confirmed to be X Drake in SBS 78 by Oda.
Here’s the excerpt:
D: “The one who was with Barrels, the pirate called “Dorry”, was X Drake, captain of the Drake pirates, right?! It struck me when I saw the name “Diez”, found the scar on his chin, and discovered that he comes from the sea of the North. So does that mean that Barrels is Drake-san’s father?” from Kobe Prefecture, Kazuki-kun
Oda: “Yes, that’s correct!! Well done with your findings. X Drake, along with Luffy and the others, is a member of the youthful “Worst Generation” of pirates that stirred up a great deal of commotion around the world. His father, Barrels, used to be a Marine Officer and Drake admired this, dreaming of becoming a great Marine just like him one day. However; who knows what happened, but his father suddenly turned into a pirate and became a terrible man who would physically abuse even his own son. Drake, who still believed in his past father and followed him around was aged 19 at this time (13 and a half years ago). Though that’s a bit too old to be calling him a boy, he probably seemed to look a lot younger while he was weakened with the fear of his father. Later, he fatefully crossed paths with Law, and the Marines soon took custody of him, leading Drake to become a Marine. The thing is, as if resigning himself to fate, after Drake made his way all the way up to becoming a Rear Admiral in the Marines, he ended up leaving the navy and becoming a pirate himself!! Just what happened? What’s he thinking? Hey, you!! —come onnnnnn. I’m interested in seeing the future of Drake, who has also made an appearance in a cover series!!”
I would like to bring attention to this part of it “Though that’s a bit too old to be calling him a boy, he probably seemed to look a lot younger while he was weakened with the fear of his father.” We can see more evidence of this in chapter 765, when Diez commands Dorry to bring more booze. We can see a tattered and bleeding X Drake in the top left panel obliging the request. Even though everyone in the pirate crew is celebrating and drinking he looks like he’s been beaten the hell up.
Anyway, we see Dorry narrowly escape the bird cage in Chapter 767, later on in that chapter we see Baby 5 and Buffalo relay to Doflamingo that the Marines rescued a young boy.
Rosinante makes note of this and on the same page says “Something’s keeping you alive” “One after another, saviours are appearing to protect you.” So by escaping the bird cage and his abusive father, X Drake inadvertently saved Law’s life as this news is what made him call off the bird cage and go searching while Law was locked in the chest. This brings me to the present, in Chapter 954 a shrouded figure lets Law escape from his cell.
The silhouette resembles the cape and shoes of Drake. It was also noted that he was acting suspiciously by Hawkins in chapter 950.
I believe, Drake, the child who wanted to become a great marine like his dad, and who was mercilessly abused when his father was a pirate is actually still working for the Marines who rescued him. This directly mirrors Rosinante’s path after he escaped the abuse for being a Tenryuubito and found Sengoku who was able to help him become a great man.
Rosinante believed “fate” was sending saviors for Law, by sabotaging the Ope Ope no Mi deal, he inadvertently saved Drake from the abuse of his father when he escaped and was picked up by the Marines. What if this came back around to now where Drake allowed Law to go free because he’s a mole for the Marines, just like Rosinante. Maybe he believes he can use the StrawHat/Law Alliance to the advantage of the Marines in taking down Kaido.
Kaido is aiming to start the biggest war ever, and you need the Marines for that. What if Drake is the man on the inside that brings them into the fold. I find it suspicious he was essentially rescued from abuse and still chose to turn to piracy.
Thanks if you read all this, let me know your thoughts.
*Theory by africhic