Total Drama / Arc Hero

Arc Hero in this series.

Total Drama Island

In Island Gwen was Heathers biggest rival alongside Leshawna and is ultimately the one responsible for her downfall. In later seasons her interactions with the Big Bad are usually minimal.

Of Action alongside Lindsay, Beth gets manipulated by both Justin and Courtney throughout the season but catches on much more quickly due to her experiences with Heather and ends up causing a lot of opposition for both of them. Culminating in her getting Courtney eliminated just before the finale.

In World Tour Heather's an Anti-Hero at best and a Nominal Hero at worst, but for better or for worse, she ends up being the protagonist who opposes Alejandro throughout the season. By the time of the finale, Cody spells it out for her, that between the two she's definitely the lesser of two evils and since she's the only one left who can take him down, that makes her The Hero.

Cameron and Zoey are this in Revenge of the Island, they spend most of the season being protected by Mike but after Scott gets him eliminated it's left up to the two of them to take him down. However in doing so they inadvertently cause Lightning to make a Face–Heel Turn and he then gets Zoey eliminated forcing him to face him alone in the finale.
Near the end of Revenge of the Island Mike becomes the main target for Scott's abuse, setting him up as this. Then it gets Subverted because the moment he finally stands up to Scott he gets him eliminated. It's then Played Straight in All-Stars as he spends the season trapped in his own subconscious by Mal and goes on a journey to save his other personalities, confront Mal and take back control.
Zoey serves this role in both Revenge of the Island and All-Stars.
- She shares this spot with Cameron in Revenge of the Island, they spend most of the season being protected by Mike but after Scott gets him eliminated it's left up to the two of them to take him down. However in doing so they inadvertently cause Lightning to make a Face–Heel Turn and he gets her eliminated immediately after.
- In All-Stars, she and Mike are the main protagonists of the season, but with Mike getting trapped in his mind halfway through the season and with Mal given free reign, Zoey is the main hero in the real world having to deal with both the competition and uncovering the truth about Mike/Mal.

Post-Merger Jasmine, Shawn and Sky become the Token Good Teammate's and throughout the remaining episodes have to deal with the Big Bad Ensemble of Sugar, Scarlett and Dave.
Despite wanting to be villain Max ends up being integral to defeating the real Big Bad Scarlett who'd been a False Friend, using him as a pawn and tricking him into hurting himself all season. He still gets eliminated alongside her immediately after because Chris was sick of Card-Carrying Villain's.
Sammy's sister Amy is the very first villain of the season's series of antagonists and she's the one who takes the brunt of her abuse. Her learning to stand up to Amy, getting her eliminated and subsequently impersonating her is a major story arc of the fist five episodes. But after that the season moves on to other stories and she and her sister are both forgotten about.

Priya and Bowie are the only ones who can keep up with Julia after she takes a level in badass so she gradually becomes the Token Good Teammate of the finalists near the end of the first reboot season. In the end she's the one who wins the final 4 challenge against Julia so they can vote her off.
While Bowie's an antagonist himself, he was the only player who could come close to putting Julia in their place and he was the definite lesser of two evils during their rivalry, his antagonistic traits pretty much disappearing around the time their true natures exposed until he gets her eliminated.