Elliot enters the book as a possible love interest, develops into a potentially murderous psycho, and goes out a pathetic pawn. Here's the skinny on each of those stages.
Always on the prowl, Vee first spots Elliot, a.k.a. Mr. Green Sweater, at a café one morning while out with Nora. He's fit and suave, standing with "his thumbs hooked in the pockets of his jeans. He was blue-eyed, with stylishly shaggy blond hair swept across his forehead" (4.41). Boy-band-cool hair aside, this first meeting sets a slightly bad taste in Nora's mouth. To be fair to Elliot, though, this isn't really his fault.
See, overzealous Vee introduces Nora by both her first and last name, which Nora feels "violated an unspoken contract between girls, let alone best friends, upon meeting unknown boys. I gave a half-hearted wave and brought my cup to my lips, immediately scalding my tongue" (4.43). Elliot knows a little too much about Nora for her comfort, which sets her on edge. At this point, Nora doesn't know that Jules has enlisted Elliot to snuggle up to Nora so Jules can kill her, but this initial invasion into the private details of life still sets the wary tone that influences their other interactions.
As the novel goes on, Elliot cozies up to Nora, switching to her school, picking her first for his baseball team in gym class, and going out to the amusement park and dinner with her. Nora is never really as into Elliot as she is Patch, and she considers him to be one of the boys "lurking on the fringe" (7.13). Until…
Well, until she finds an article about him online linking him to the suspicious death of Kjirsten Halverson, an eighteen-year-old girl found hanging from a tree on Kinghorn Prep's campus, which totally brings up images from slasher-flick. Definitely creepy.
Nora begins to suspect Elliot is the dude in the ski mask, and he does nothing to discourage her thinking, becoming increasingly violent toward her and even showing up at her house and pushing her around when she refuses to go away on a camping trip.
But Nora's uneasiness around Elliot brings up an important question: Nora finds Elliot threatening, so she stands up to him and avoids him. Nora also finds Patch threatening, but she is drawn to him and continues to spend time with him. What's the difference?
Patch and Elliot have some similarities. They're both good-looking—Patch in the tall, dark, and mysterious way, Elliot in the blue-eyed, blond-haired way—and they both express immediate attraction to Nora, each pursuing her aggressively. Before Nora starts to get suspicious about Elliot, she compares her two potential boy toys:
I did not like the idea of Elliot going head-to-head with Patch. Patch was an X factor: intangible, scary, and unknown. Who knew what he was capable of? Elliot was far too nice to be sent up against Patch. (7.92)
Okay, so Nora could not be more wrong about the "too nice" characterization, but there is something in her observations of Elliot being flat and one-note, while Patch has "X factor" appeal and charisma.
Plus, when Nora discovers the article about Kjirsten's death, she has hard evidence that Elliot has been mixed up in seriously dangerous business. When Nora rejects him, he threatens her, gives her ultimatums, and pushes her around. He also shows up at her house drunk, indicating a lack of control. Elliot, then, sends up all kinds of red flags.
Patch, on the other hand, gives off more intrigue, displaying more stereotypical "macho man" qualities, like being protective and providing, in addition to being predatory (hop over to his page elsewhere in this section for more on that). Compared to Patch, who exhibits a mishmash of dangerous and desirable masculine qualities, Elliot only displays a dangerous and predatory nature.
Everything seems to be on pace for Elliot to be the book's ultimate bad guy as we head into the final showdown at the high school. Elliot calls Nora and tells her she'd better come to the high school for a nighttime game of hide-and-seek… or else Vee will meet the same fate as Kjirsten.
When Nora gets there, though, she finds Elliot severely wounded and discovers that Jules is really the evil mastermind behind it all. And so our view of Elliot shifts into phase three: the pathetic pawn phase.
No doubt about it that Elliot is still a bad guy, but he's not the bad guy—that prize goes to Jules. Instead Elliot's more of a spineless, money-grubbing, weak tagalong. Jules is Elliot's benefactor and coerces him into doing terrible things, such as kill Kjirsten, by threatening to cut him off. Like Nora, we don't feel that he deserves a slow and painful death at the end (and the police do get there in time to save him), but beyond that, we don't really care about him because he has such flimsy moral character.