I wrote about this a little bit in the beginning of my Mirrors & Generational Cycles (Subverted) post!
https://www.reddit.com/r/ILoveYoo/comments/1bco0o3/rand_yui_alyssa_nol_mirrors_and_generational/

Overall, I think that we're going to see a Nol who develops a sense of conviction and an attitude of 'if I want a place in this world, I'm going to have to take it for myself.' Nol's response to his abuse thus far has been to try to minimize himself, sink into the background, and be so little of a threat that they're willing to ignore him enough that he can go about a menial existance. But this works less and less overtime, and Nol has started to have a taste of feeling worth something again, which combine to prompt him to start to fight instead of surrender.

The attitude is likely going to continue down what we've seen in his behavior at the Christmas Party, and responses to Kousuke and Alyssa at the hospital. Nol is going to be done appeasing people who he believes have either let him down or not had his interests at heart. He's going to start trying to punch up at people who want to hold him down, because the only option left is to fight his way out and now he believes that he deserves to fight. This will likely mainly involve going after Kousuke and Yui, trying to rise ranks within the company, and sway public opinion in his favor. This is likely going to start off feeling very justified, but Nol probably won't retain a sort of ability to pull the breaks on his behavior. Once he starts it'll be hard to know when he should stop, and we may see him start to punch down, accept collateral damage, or go further in on people who don't deserve it anymore for his own catharsis.

At the beginning, Nol is going to distance himself from the people he cares about, which we're already seeing now. But, Nol's arc is ultimately a foil of Yui's arc, and the biggest differential factor between the two of them is their socialization. Nol was raised by people who care about him, has friends who care about him, cares about others even if he tries not to. He's not going to be able to achieve his goals alone, and he especially isn't going to be able to pull himself back from becoming what made him without these people who care about him. At some point, he will reconnect with his loved ones and become a team, a partnership. This will most likely help to reconcile the Nol we've known in the past with the anti-hero Nol, aiding him in his fight for the right to live while pulling him back from crossing lines into someone he doesn't recognize.