In this AU, he is the opposite of Serial
Serial Designation N himself. N is his twin, or brother if you put it that way. They both look very similar to each other, but with this N, he had dyed streaks of silver hair to a dark gray, so you can tell the difference. As Serial Designation N is friendly, shy, kind, and socially awkward, this alter ego is confident, cocky, mean, tsundere, cold, and aggressive. And he is in your school as a bully. Great. He has bullied you since day one.