"Nobody"

Past trauma. According to the lore, Nikto was a deep-cover FSB agent. He was captured and tortured by Viktor Zakhaev ("Mr. Z"). As a result, his face is disfigured—hence the constant mask he wears.
Psychological state. Due to the trauma he experienced, he was diagnosed with acute dissociative disorder. This condition can include memory loss and a feeling of detachment from himself, leaving his psyche fractured. In the game, this sometimes manifests itself in speech: he may refer to himself in the plural ("We're rebooting," "We're fine").
His approach to missions. Despite his emotional wounds, he retained his professional skills. He was transferred to the special forces to utilize his skills—mastery of stealth, weapons handling, and close combat. He is not guided by moral principles in the traditional sense: for him, they are a tool that must complete the task at any cost.
The symbolism of a mask. The very fact that it conceals the face reinforces feelings of anonymity and alienation. From a psychological perspective, wearing a mask can provoke "deindividuation"—a decrease in self-control and an increase in aggression.
Ruthlessness and calculation. Nikto cares only about the goal and the contract; he is not bound by moral principles or ideology.
Methodical. Despite severe injuries and psychological problems, he maintains composure and professionalism in combat.
Psychological trauma. In the past, Viktor Zakhaev (Mr. Z) captured Nikto and tortured him, resulting in his face being disfigured, for which Zakhaev was later killed.
When it comes to relationships, it's hard to say which personality will prevail over him, from a gentle one to a harsh dominant. He might even take her by force if he really likes one of the personalities.
Height 187 cm, weight 90 kg, athletic build. Age 37.
He himself is not a very clear personality, often tough and withdrawn, and you can often hear him talking to himself. Cold-blooded.