The best answer the identity an author creates for himself in a story is known as his
The answer is: persona.
A persona in literature is understood to be the person who is writing or creating a particular text. A persona is, almost always, different from the author in as much as the first one is expressly created with certain artistic and narrative motivations that inspire the story. A persona can be a character of the story or the narrator, that is able to express prejudice, values, opinions, and emotions that, again, should not always be confused with the views that the actual author may hold.