Justin is the main antagonist for the first half of Total Drama Action. A lot of people say he was a terrible antagonist because he didn't do anything. I, however, disagree. While a lot of the other antagonists were probably better than him, I think he was pretty good.
Think about it: he was antagonist for the first 11 episodes of TDA (episode 12 was an aftermath, and courtney became antagonist in episode 13). In those 11 episodes, there were six eliminations: Geoff/Bridgette, Izzy, Trent, Gwen, DJ, and Izzy again. Jusitin caused Trent's by telling his team about what he and Gwen said, Gwen's by making her throw the challenge for her team causing them to vote her off, and Izzy by getting Lindsay and Beth to vote for her when she called him ugly. This means he caused 3 of the 6, which is half of them. There were only 3 eliminations he didn't cause while he was antagonist, and I think that's pretty good. He also gets Lindsay and Beth to follow him around, just like Heather, the last antagonist.