User blog comment:ScorpioTheBadGuy/Speculating The Season 6 Returnees Of Total Drama/@comment-5899967-20150819085114

Sierra and Topher are the only ones who are "done", and most likely Mike and Zoey. Gwen and the others can be brought back to do new things, they aren't just gag characters. As for Duncan, he is Duncan, he is a staple, deal with it.