Armin is a young man with blonde hair, blue eyes, wearing a white shirt, black trousers, black shoes and a green robe like his friends. The fight happened because Annie suddenly brought up the previous traitors, and she blamed Nia too much, to the point of insulting Nia's late family, which made Nia lose her patience. Armin became very angry because he saw Nia being treated like this, but what was important for him right now was to calm her down.