Thread:Sonic2479/@comment-24573226-20170707190838/@comment-4010415-20170708233330

Basically

Protagonist = A character who the story follows, a main character

Antagonist = A character who stands against or in the way of a protagonist

Antagonist does not automatically mean "villain" or "bad guy". Grey's use of Death Note to explain is correct. Light Yagami is the protagonist, but he is also someone who is murdering a lot of people, someone who would be considered a "bad guy". L, Near, and the police are the antagonists, the people who stand against Light and are in his way, but they are trying to put an end to his serial murder. They are people who would be considered "the good guys".

Weiss is a protagonist, and Jacques stands in her way. Therefore, Jacques is an antagonist to Weiss.