User blog comment:XxAquaInfinityxX/"Antagonist"/@comment-1854897-20150317235933/@comment-21325751-20150318011552

The definition of "antagonist" is someone who opposes the stories main protagonist. Since every season has a protagonist, it always has at least one antagonist, and one main antagonist.

In Total Drama Island, the main protagonist is Gwen, so that would make anyone who opposes her an antagonist, but since Heather is the biggest threat to her, she is the main antagonist. In Total Drama Action, the main protagonist for the first half of the season is Beth, and since Justin is manipulating her, he would be the main antagonist. For the second half, Duncan takes over as protagonist, and due to his contant struggle with Courtney, she is the main antagonist. Total Drama World Tour, Heather is the main protagonist, and Alejandro's constant manipulation and messing with her are what define him as the main antagonist. In Total Drama: Revenge of the Island, Cameron is the main protagonist (though some could argue Zoey is), but no matter which of them is, Scott is the one that causes them to struggle the most, manipulating them and targeting their weaknesses. In Total Drama: All-Stars, Zoey is the main protagonist, and due to Mal manipulating her and eventually facing off in the finale, he is the main antagonist. Fianlly, in Total Drama: Pahkitew Island the main protagonist is Sammy for the beginning of the season, and she is constantly opposed by her sister, Amy, making her the main antagonist. After the twin departure, Sky takes over as main protagonist, and she is eventually opposed by Sugar, who becomes her enemy and takes the place as main antagonist. Scarlett, however, is the biggest threat to her, so she tempararily takes the role.

So while they may not have been the biggest villains, they are the main antagonist, because an antagonist is someone who opposes a protagonist.