Each 2P personality is depicted as having reversed or opposing personality traits compared to the original character. For instance, a country that is portrayed as cheerful and optimistic in their original depiction may have a 2P version that is gloomy and sarcastic. These alternate versions are often used in fanworks such as fanfiction and fan art to explore different aspects of a character's personality or to create darker or more complex storylines.
It's important to note that 2P personalities exist exclusively in the realm of fanon (fan creations) and are not part of the official Hetalia canon or recognized by the series' creator, Hidekaz Himaruya.