In the story I'm writing, I want to include a character who is a free radical. At some points she helps the main group and at some points she hinders them. She may even end up joining the main group if events lead to it.
So my question is, since she isn't really entirely an antagonist nor a protagonist, is there a third category that she would fall in?
In classical theory, this character is known as the trickster. https://en.wikipedia.org/wiki/Trickster They are the chaotic character. They create problem for the protagonist because they cannot be relied on, but nor are the necessarily an enemy.
This is best described as a Supporting Character, because they are neither good, nor bad. They simply quote "support the story line"
I think that the answer depends on whether this is a, or the, main character in the story.
The main character or main plot-driving character is the protagonist. Someone who opposes their goals is an antagonist--and often there is a "the antagonist" vibe, where the primary character opposing the protagonist is "the" antagonist.
Now, it's not always this neat. Bill and Ted's Excellent Adventure, for example, arguably has two protagonists. In the 1993 The Fugitive, Tommy Lee Jones' character is arguably the antagonist, except toward the end he turns around and he's helpful. In The Great Gatsby, the main plot-driving character, Gatsby, is separate from the character that we identify with, Nick Carraway. And so on.
Nevertheless, I think that the designation of protagonist/antagonist depends on who the main plot-driving character is, whether the character you're trying to classify tends to champion or sabotage their goals, and how important that character is.
I think this would count as Deuteragonist. Not the main character, but not a complete antagonist. The biggest example for these are sidekicks and allies, but they don’t have to be helping the protagonist always.
I would consider them somewhat of a contagonist as described in Dramatica. The contagonist doesn't necessarily help the contagonist but they do hinder and interact with protagonist.
Anybody who’s “poly-tagonistic” in a sense, in my opinion, is simply human. We all battle our whole lives attempting to discern right from wrong. And if you aren’t, then you’re most likely a nihilist. It’s the Tony Stark method. Anti-hero! An individual who desires to be a savior, unknowingly creates all his worst fears that he manages to physically manifest, forcing him to become,”the hero” A lot like our government.
SHAPE SHIFTER
I think what the actual questions tries to convey is how you call a character that is not good or bad, more like indifferent to the main storyline (the story the reader or viewer is following). In literature we have the “hero”(we all know that one) the “anti hero” (the average person, unlikely to succeed in life who gets trapped in a complex series of problems, mostly unwillingly), the “unsung hero” (the one who sacrifices himself and nobody notice, except the reader/viewer). In the lord of the rings Aragon would be the hero, Frodo the anti hero. In “his dark materials” Lord Asriel and Mrs Coulter would be unsung heroes.
The question remains: what do you call characters like Illyria in Angel (spin off of Buffy), Seshomaru in Inuyasha, Cat and Fish in Gotham, Severus Snape in Harry Potter, Nebula in avengers or androids 16,17 and 18 during the second arch of Dragon Ball Z???
The tricksters? Don’t think so since they just find pleasure in causing problems but never cross certain line (which will turn them into villains) they have a tendency to add a certain sassiness and humour to their character (Loki in avengers)
Mostly this kind of characters feature in science fiction and anime, and I think the correct term (literary term) is “THE SHAPE SHIFTER” the one who goes from bad to good or vice versa, but of course it depends on the storyteller at which point it turns from a shapeshifter to a guardian or antagonist. Since most of this characters share one thing in common (an stoic demeanour) I like calling them the stoic heroes (if they go from bad to good or stay ambivalent throughout the story) but I suppose shapeshifter IS the cannon.
