Changing the narrator of your story can impact it in several major ways.
"The author gives an actions of the main character that will lead another character to do something, changing the story." by Naheem D. King
A character arc or change from one personality or attitude to another is typically representative of a dynamic character. Dynamic characters undergo significant internal development or change throughout a story, as opposed to static characters who remain unchanged.
A dynamic character is a character who learns things throughout the story, and who changes. A static character is just the opposite; a character whit less traits, and does not change much throughout the story.
A catalyst is a character tha brings about change in the story. For example, a catalyst's actions could cause one character to lose trust in another, or something of the sorts. Basically, if the story takes a different course because of a certain character, that character would be a catalyst.
Character development or character arc.
If you mean a 'main' character in your story, you could say a "protagonist"... or a figure.
In "The Adventures of Huckleberry Finn" by Mark Twain, Stephen Dowling Bots is not a character in the novel and does not die in the story. It is possible that you may be confusing him with another character or story.
You could either be referring to a flat character (characters in a story who do not go through substantial change or growth throughout the story) or a static character (a character who goes through no change)
A catalyst is a character tha brings about change in the story. For example, a catalyst's actions could cause one character to lose trust in another, or something of the sorts. Basically, if the story takes a different course because of a certain character, that character would be a catalyst.
In Greek mythology, there is no character named Eleanor associated with Odysseus or his adventures in the "Odyssey." It is possible you may be confusing her with another figure, such as Penelope or a character from a different story. If you meant another character or event, please clarify, and I would be happy to help!
a flat character **
static minor character