TV-Series
Description
Nyx is a British intelligence agent who appears in the anime Lupin III: Part IV as a recurring adversary. His code name is Nyx, and his real name is Justin Person. According to his backstory, Nyx joined the British intelligence agency MI6 before the events of the series, and during his time there he was subjected to experiments that gave him an exceptionally heightened sense of hearing. His hearing works in a manner similar to echolocation: by using ultrasonic waves, he can accurately read the location of a target and perceive his surroundings without relying on sight.

In terms of personality, Nyx is methodical, disciplined, and highly composed. He treats his assignments like mathematical problems, calculating every step to produce the best possible result, and he rarely allows emotion to interfere with his work. His main motivation is to complete the missions assigned to him by MI6, which regularly puts him in opposition to the thief Lupin. Early in the story, Nyx succeeds in capturing Lupin and is then ordered to recapture a treasure that Lupin has taken, forcing him to chase the escaped thief across the series.

Nyx operates under the command of the MI6 officer Percival Gibbons, and his role in the story is that of a capable and persistent enemy of Lupin. Despite his professional detachment, he has a personal side centered on his family. When his daughter is kidnapped, his usual composure begins to break down; the threat to his family pushes him toward reckless behavior and reveals an emotional vulnerability beneath his calm exterior. Lupin becomes involved in the kidnapping incident and helps resolve it, which complicates the relationship between the two men. Their dynamic gradually shifts from straightforward hostility toward something more nuanced, and in the later part of the series Nyx is shown attending a dinner arranged by Lupin alongside other acquaintances, indicating that the two have reached a more cordial understanding.

Nyx's defining ability is his enhanced hearing, which functions like echolocation and allows him to pinpoint the position of people and objects with great accuracy. Combined with his calculating mindset and his training as an intelligence agent, this makes him a difficult opponent who is able to catch Lupin off guard and match him in the contest of wits that runs through their encounters.