One could argue that there are several antagonistic forces at work in Faulkner's "A Rose for Emily." First, the obvious antagonist in the story is the culture of the town that impedes Miss Emily's character and causes her to live as a recluse. She appears to not want to be judged by the townspeople and as a result closes herself off from them.
However, other forces in the story are antagonistic such as Homer Barron and Emily's father. These men attempt to form and mold Emily according to their own whims and beliefs. They do nothing to nurture her character. But Emily is perhaps her own antagonist--she cannot deal with her personal sense of loneliness, and she allows her feelings to consume her. Loneliness leads Miss Emily to commit murder and from this she never recovers.