This is one of those stories for which these character archetypes work well. As both of you have suggested, the Nemesis function is provided by Silas. Since she doesn’t actually confront him until Act Three, there is a series of characters who provide opposition to Erin, often only until she beats them into confessing a key piece of information in her clue-gathering mission to track down Silas. That’s a case in which for those interactions, the characters don a nemesis ‘mask’ in opposing Erin. All except for Toby who definitely fits the mold of a Trickster with his demand for a ‘hand job’ in exchange for his info.
Shelby is an Attractor character, but so is Chris. It would be one thing if Chris were just a memory, but in the script he comes to ‘life’ through a series of flashbacks and we see how their relationship grows from professional to personal to really personal when Erin becomes pregnant.
Just as Erin meets a variety of characters who provide opposition to her, performing a Nemesis function in those key scenes, she also has some characters who try to steer her away from the doomed path she’s choosing. Ethan, Gil, Antonio, each in their own way conveying ‘wisdom,’ essentially “don’t do this.”
Of course, Erin refuses to listen to them. This is the journey she MUST go on. The source of her Disunity state at the beginning of the story is the bank robbery gone wrong years ago resulting in the deaths of Chris and the innocent bank teller. She not only suffers from survivor’s guilt, Erin also knows she is directly culpable for what went down because it was SHE who suggested to Chris — and convinced him — to take some of the cash and go off to lead a different life together.
She will forever be stuck in a downward psychological spiral unless she confronts her past. The purple dye dollar Silas sends to her is a Call To Adventure to deal with her tragic past. Thus, her clue-gathering journey to find Silas is akin to her descending — psychologically — into Dante’s Inferno, each step closer to Silas requires her to go one level deeper into the layers of guilt and shame she feels about the past.
One of the major strengths of the script is the psychological connection between the Protagonist (Erin) and Nemesis (Silas). Not just a generic Good Gal vs. Bad Guy. No, it is a specific connection. Whether she realizes it consciously or not, Erin’s journey is one of Redemption. She cannot save Chris. Nor the dead bank teller. But she can square things by slaying Silas, their murderer. And in the subplot with her daughter, she can take what’s left of her blood money and buy off Jay, thereby — hopefully — freeing Shelby to NOT follow a destructive life-path like that of Erin.
And, of course, Erin has to die. That’s her fate. Slay the ‘dragon’ who torments her (Silas) and sacrifice her own life in the process. In a way, she deserves to die — I suspect she actually feels this in her gut — but her actions allow her to die on her own terms having succeeded in cleaning up the mess she helped to create. One hopes she experience at least a flicking moment of peace before her life slipped away.
So Destroyer is yet another movie for which these five primary character archetypes work. The interesting thing is that storytellers don’t have to have any conscious awareness of these archetypes in crafting their stories, rather their respective narrative functions just naturally seem to emerge in story after story after story. This construction of characters may not be as universal as the Hero’s Journey, but at least as far as movies and even some types of television series go, it does seem to have a pronounced presence.
It’s something we, as writers, can use to help wrangle the characters which emerge in our brainstorming by zeroing in on their respective narrative functions and using that as a lens through which to interpret who they are, how they are, and why they do the things they do in our stories.