In poetry, a heteronym is one or more imaginary character(s) created by a poet, to write in different styles.

Fernando Pessoa is the poet best known for the use of the heteronymic device. It is said that Pessoa had over fifty heteronyms living inside of his head, each with a different manner of writing, preferences, likes, dislikes and even varying mother-tongues. Some of these were poets while others wrote fiction. Additionally, the heteronyms criticised each other and oftentimes got into arguments. Fernando Pessoa To meet Wikipedias quality standards, this article may require cleanup. ...

One heteronym even attempted to break up Pessoa's only known relationship with a woman and even penned a letter to her on behalf of Pessoa.

This behaviour is often associated with people who have a natural desire to be alone.