He is extremely amoral in his methods, noted to use any and all means available to successfully complete his mission. He shows no loyalty to others as he is willing to use any "teammate" he is working with as bait or as a tool to get himself any advantage if possible, even if means endanger them greatly. He is, however, not above saving them if it proves too dangerous, after they served their purpose. He is very dishonest and manipulative, constantly using lies and traps to deceive his enemies.
One of his most noticeable traits is his loathing for over-dependence on AIs, stemming largely from the accident that ruined his life. Ultimately, he only sees them as a tool for humans to exploit and otherwise disposable. Kengo projects his intense hatred towards AIs into the Ignis, which he became obsessed with destroying.
Despite his ruthlessness, Kengo displays a soft side for his younger half-sister, Emma, as seen when he saved her during the bounty hunter mission and when he decided not to erase her LINK VRAINS account after defeating her. He also showed a bit of sympathy towards his late father by bringing flowers for his grave
As noted by Varis, Kengo displays a strong pride in being a bounty hunter and acting on his own, sometimes to the point of stubborness. Varis described Kengo as "A lone wolf" because of this