this is the MC talking to you. That's why he says you already know his name but doesn't state it, you're the one that gave the MC his name. This is him left over after everyone is deleted, and there is no one else in the game world. the kernel access passes down to whoever is class president, and since no one is left besides the MC, he is left with kernel access. He doesn't fully understand the code though and mentions that. He also knows about The Third Eye because he read the Portrait of Markov with Yuri (kernel access and being able to see the game code = third eye?). There's probably more to it, but I don't think there's any other explanation for it. I really don't think its Monika.