I think it’s best we are lead to believe that in the film his greatest antagonist is the leader of the bullies. ?But as the protagonist changes in the story he realizes his fatal flaw is his inability to take a chance (for fear of failiure). ?So what we realize is that HE is his own biggest antagonist, and in actuality the bullies provided him with the opportunity to look inside himself. ?He matures more throughout the film and realizes he can’t live in a shell he has to take chances and that’s part of life. ?and perhaps in the end he actually befriends the bullies and they also change. because in high school pretty much everyone is dealing with their own growing pains in weird ways.