Akira 'AJ' Juniro Isaki, also known as Switchblade, is a member of the Japanese Blood Brotherhood, working in the U.S. Marines.
Akira Isaki was born in the United States to a mixed-race American and Japanese couple. However, only a year after his birth, both of his parents were killed in a car crash, and Akira was subsequently raised by his Japanese-originating grandparents.
However, as they had been imprisoned and mistreated in a torture camp during World War II and felt bitter about Japan's ensuing humilation, Akira's grandparents taught him to be hateful towards the rest of the world, setting himself a duty to restore Japan's honour.
In order to do his part, Akira joined the United States Marine Corps, gaining the call-sign Switchblade. He eventually requested a transfer to the Commander-in-Chief's In Extremis Force (CIEF), who were heading up the Machine restoration mission. Eventually Switchblade was promoted to be Wolf's personal bodyguard.
Shortly after Black Dragon's failure to secure Jack, Lily or the Firestone, Switchblade accompanied Wolf. After Wolf gave Rapier his instructions for their next move, he requested Switchblade leave him alone within the farmhouse for a few moments, to which Switchblade complied.
When the coalition of minnows rendezvoused at Mortimer Island to make use of the Sacred Stones and Pillars they had obtained thus far, Switchblade stood by Wolf's side as they watched the proceedings via the base's security feed.
After some of Jack's team were captured and imprisoned in Wolf's mine in Ethiopia, Switchblade remained silent as Wolf spoke to his son. After Jack was left to be crushed beneath a stone slab, Switchblade inquired as to what they would do with Pooh Bear and Stretch, and after Wolf revealed his plans for the pair, Switchblade joined him as they left the mine.
During the CIEF's search for the Neetha tribe, which possessed the second Pillar, the Brotherhood got in contact with Switchblade and gave him leave to sabotage Wolf's efforts to lay the second Pillar.
Switchblade and Broadsword were among Wolf's hired Congolese mercenaries who tracked a rogue Huey signature believed to belong to Epper's people. After neutralising natives who were trying to sneak up on them, Switchblade joined in on the assault on the village. During the attack, he managed to clip Alby Calvin's arm, preventing the boy from escaping with the rest of Epper's team. When the attack was over, Swtichblade reported to Wolf that they had claimed the Philosopher's Stone and Firestone in addition to the first and second Pillars, the capture of Alby, and the Neethan Warlock, who offered to show them to the second Vertex beneath Table Mountain.
After the CIEF had made their way through the traps of the second Vertex, Wolf sent Switchblade and Broadsword to lay the Pillar at the inverted pyramid. Before Broadsword could set the Pillar in place, Switchblade slit the Delta operator's throat and shouted to Wolf his nation's dishonour would be avenged as he prepared to drop the Pillar into the abyss below. However, Jack swung out to the pyramid's tip on a Maghook, grabbed the Pillar as Switchblade let it go and placed it just in time.
Furious and with no way out, Switchblade decided to take one of his organisation's enemies with him, and allowed himself and Jack to fall into the abyss, appearing to all those witnessing that they were falling to their deaths.
As he and Jack fell, Switchblade gloated that despite his failure they would die together. However Jack wasn't finished, and took Switchblade's Maghook from his back holster and fired it into the abyss wall, stopping his fall. Switchblade was horrified that he had been completely beaten and that he had died for nothing, and continued falling to his death.