Antagonist
Character Role Analysis
Olivia, Black Arthur, Pretty Much Everyone but Alan… Oh Yeah—and Alan, too
Um, yeah… Nick butts heads with a lot of people—pretty much everyone but Jamie and that's only because Jamie is gifted at avoiding conflict. He even gets into it with the one character he seems to sincerely like, his brother, Alan.
If we had to pick just one antagonist, we'd probably go with Mum/Olivia because it's pretty obvious from the get go that she has zero interest in seeing Nick do well, be happy, meet somebody, settle down—you know, the things parents usually wish for their children. Instead it seems like she'd feel better if Nick would just disappear, fall off the face of the earth, or otherwise cease to exist. And of course, there is also the fact that she tried to drown him when he was a baby… Now that's antagonism.