The main charachter is usually reffered to as the protagonist(or the good guy) and the person that he/she conflicts with is usually refered to as the antagonist(or the bad guy).
The main mentor in Divergent is Tori.
Divergent was written by Veronica Roth.
Divergent has been challenged.
There really isn't an antagonist.
The antagonist in the book Matched is actually not a single person--so the question is actually "what" and not "who" :) Getting to the point, the antagonist is the Society which controls every aspect of the citizens' lives and grants them no freedom. They decide for what you eat, when you die, how much you exercise, who you marry, what job you have, your education in school, and much more.
divergent
antagonist
It is called a divergent plate boundary.
divergent are kisses
Not always true. Eg the divergent series 1,0,2,0,3,0,4,... has both convergent and divergent sub-sequences.
Older material
If antagonist did not want to harm protagonist, he wouldn't be antagonist. His opposition to protagonist is what makes him antagonist.
Convergent on the western perimeter, divergent on the Easter perimeter.
Antagonist or villain.
Bryce is the antagonist.
Cory is the antagonist.