Character Analysis
Hellraiser
Eric is the closest thing resembling a villain that we get in these four Four stories. We're reminded of all the piercings in his face so many times, he starts to look like Pinhead from Hellraiser. and Eric does like to raise hell. Four pegs him early on as "someone to watch out for. Maybe even someone to be afraid of" (1.275) because Eric, a transfer from Erudite, knows who Four really is (Tobias Eaton) and is itching for the right moment to use that knowledge against him.
For Four, having his past identity exposed would be the worst thing ever.
We learn later on that Eric is Jeanine Matthews's lackey, and that he's been passing information "anonymously" to her about Four's test results. This info causes Jeanine to suspect Four might be Divergent. It also leads her to suspect Amar is Divergent, which leads to Amar being "killed." (Spoiler alert: In Allegiant we learn Amar is still alive.)
Eric rises to the level of Four's antagonist in the third story, "The Son." Both Eric and Four are up for the position of Dauntless leader. Eric ends up getting it, and not because he's more qualified than Four, but because he's more easily manipulated. However, as a result of this appointment, Dauntless becomes the dangerous dystopian place it is in Divergent.
Four threatens Eric often to try and stop him, but this is one situation in Dauntless that violence cannot solve. Read more about Eric here.