Sakazuki

Sakazuki, commonly known by his alias Akainu, is the current fleet admiral of the Marines, succeeding the previous fleet admiral, Sengoku. During the first half of the series, he was one of the three admirals, and the last one to be fully revealed. He ascended to the position of fleet admiral after defeating Kuzan in a ten-day duel that left Punk Hazard in its current state. One of his first decisions was to relocate the Marine Headquarters into the New World in preparation for the New Pirate Age. As the current fleet admiral, Sakazuki has control over the entire Marine organization, from ordering all soldiers and officers as he sees fit to issuing a Buster Call on any island he deems to be a threat, and to revoke any Shichibukai's title at any time, as well as including the authority to promote and demote any Marine's as he sees fit on top of granting the power, and authority to either temporarily grant others similar authority and power, or near-permanent power to anyone he wants, or has to. His only superiors are the World Government's Commander-in-Chief Kong and the Gorosei. Sakazuki's background, specifically his black-hearted behavior, is renowned, especially among the stronger figures in the New World, striking fear into the hearts of pirates and marines alike. After Van Augur identified Akainu aboard a marine ship for negotiations, Blackbeard immediately fled, knowing the consequences of battling against him, even after Blackbeard had gained the powers of the Gura Gura no Mi, and strengthened his crew with several of Impel Down's most powerful criminals.

Fleet Admiral Sakasuki

Many within the high ranking echelons within the World Government suggested Akainu to become the succeeding fleet admiral over Sengoku's personal recommendation for Kuzan, thus further supporting his incredible military might. Furthermore, Jinbe noted the Marines have become a much more powerful organization under Akainu despite the resignations of Garp, Sengoku and Kuzan, indicating great leadership on Akainu's behalf. Sakazuki later had a meeting with the Gorosei and a heated argument broke out between them. After learning that the false news about Doflamingo leaving the Shichibukai was by the order of those above them, he angrily asked the Gorosei why the whole world had to be misled for Doflamingo's sake, noting that if an incident like this were to occur again, he as fleet admiral would be disgraced. The Gorosei ignored him, saying that they were not concerned with his reputation as the Marines are only the public face of the World Government. When he was told that the case had been left to the Cipher Pol, Sakazuki retorted that even the Gorosei had been walked over by the "Celestial Dragons' puppets".

Akainu

The Gorosei responded in anger, blaming Sakazuki for Kuzan joining Blackbeard. Sakazuki replied that Kuzan's actions after he left the Marines were not his concern. Suddenly, a Marine interrupted the meeting and reported about what transpired on Dressrosa. Sakazuki then contacted Fujitora and scolded him for allowing the true news of what transpired at Dressrosa to spread throughout the world without the consent of those in the higher echelons. He angrily told Fujitora that he should know what it means for him to admit fault, and that he should have reported it before taking action. Fujitora replied if he had done so, the incident might have been covered up. Sakazuki suggest that cover-ups were needed in order to save the face of the World Government. Fujitora stated that he does not want to be made into a hero for something he did not do, and that the World Government needs to take responsibility for their actions. Sakazuki shouted that it is a matter of credibility and trust, but Fujitora responded that if such meaningless trust is important it would be better not to have any. Sakazuki then demanded Fujitora to bring back the heads of Luffy and Law as recompense for his actions at Dressrosa, and forbade Fujitora from entering any Marine base until he carried out this order.