As almost everything about this movie is atypical — from the concept to narrative structure — so, too, the characters at least insofar as their respective archetypes are concerned. Here’s my take:
Protagonist: Joel. It’s his story, told through his perspective, all the characters are somehow connected to him, and he goes through the most significant metamorphosis.
Attractor: Clementine, although one could make the argument she is a Trickster because she wears that mask a LOT. Still, I think of her as an Attractor because she is the focus of Joel’s emotional life… throughout the movie no matter the ups and downs of their relationship.
Mentor: In a previous discussion of the story, someone suggested that Memory Clementine — the iteration of the character Joel remembers — pretty consistently tries to steer Joel through his emotional roller coaster back to Clementine. That’s an interesting take.
Another idea is that Dr. Howard Mierzwaik is a kind of Negative Mentor in that he’s the inventor of the erasure process which, as the movie suggests, is a dangerous application. Mierzwaik has deep insight into science, but in this case, the process is a net negative for Joel.
Trickster: Well, there’s Patrick who attempts to steal Clementine away from Joel. In fact, the entire Lacuna team could fall into the Trickster category, at first allies (ostensibly) to help Joel achieve his want: erase his memory of Clementine. But actually enemies because…
Nemesis: I think the memory erasing process itself functions as the Nemesis. It is a morally corrupt concept to begin with. Memories, both good and bad, comprise much of who we are. To think by erasing the bad ones that would be a plus is to eradicate a significant aspect of one’s personality. Moreover, who can project what impact the erasure can have on the patient. It could be positive, it could also be negative, maybe even hugely so.
Indeed, at a key juncture in the story, Joel’s want changes: He wants to STOP the erasure at which point the procedure has definitely moved into an oppositional mode.
So that’s my take. How about yours?