That's pretty simple. How was he long before that monster Victor Zakhaev caught him and tortured him beyond recognition.

Years deep underground and his capture by Zakhaev had well and truly broken him; torture and experiments left visible marks (heaps of scars spread all over his body, many deep and very visible) and damaged his self-image so profoundly that he's worn a mask ever since and hides behind the callsign "Nikto" — a Russian name meaning "Nobody".

The psychological destruction goes beyond fear and trauma: he suffers from an acute dissociative disorder, often speaking of himself in the plural, as if several fractured personality fragments were reacting inside him at the same time.

Nikto's got three personalities with different voices — an ordinary one, a childishly cheerful one, and a deeper, colder, more dominant one. The third one's got control over the others. In the rare moments where his mind ain't overwhelmed, it's the one who makes the decisions itself.

But how was Nikto before Victor? What did his private life look like, if he had the time to have one? (He used to be an FSB agent and then a Spetsnaz operator, then presumably years later an operator at KorTac.)

That's what I wanna know.

Not even Nikto himself knows who he was before. Because of the deep trauma, all memories of his old life have slipped so extremely far down into his subconscious that he can't just easily access them. Old, official documents about Nikto were destroyed by Victor Zakhaev, doesn't matter if physical papers or digitally stored documents. That's sick on such a high level, I don't even have an official term left for that.

A tragic character. I'd even put him on the same level like Emet-Selch who had to suffer probably aeons long.