Appearance in UltimaEdit
The TD Teens made their debut in the Ultima story, Total Drama Ultima where against all odds, they survived their world's destruction and reunited with each other (with some help from Clockwork). Because of their bravery and strong will to fight, they became the very first Society Sentinels inspiring other refugees to train and fight against the Org, and all other evils in the multiverse.
The only TD teenagers who have yet to appear in any of the stories so far are Alejandro, Sierra, and the contestants from the Total Drama: Revenge of the Island. They will make their debut in Total Drama Ultima II.
However, what the TD teens don't realize is that there are alternate universes to the Ultima universe, and their world of Camp Wannaweepke has an alternate universe of itself where the inhabitants are a little bit more antagonistic than the normal universe teens. It was this group of A.U. TD teens that was kidnapped by the Mad Doctor and had their hearts stolen by the Heartless in order to create Nobodies for the Circle of the Blot. And since Nobodies in their normal selves are not actually evil, the alternate TD teen nobodies were implanted with shards of the Shadow Blot's soul that would slowly over time grow into a full heart of darkness and turn them into vessels for the Shadow Blot to possess. Already the heart shards have turned the Nobodies into spiteful and wicked warriors of darkness, which is perfect for the Mad Doctor's plans to inevitably pit these evil alternate dopplegangers with their normal Sentinel counterparts.