"Is it wrong to lie to yourself and keep on loving the same person wronged by destiny? Or is it worse to lie to yourself and keep on loving the same person wronged by luck?" ― Stefan in Ultima Petitio
Stefan Deveraux is the one of the main male protagonists of Ephemerality. Stefan's family was a native of Thornwood, yet it was the first time in eighty years that the remaining Deveraux would come back to Thornwood after their ancestor, Leandre Deveraux, fled the town. He is the son of Flynn Deveraux, and the older brother of Selene Deveraux.

At the beginning of the book, Stefan was first seen together with Veronica Mizuno, his girlfriend and one of the antagonists of the first book. We later learn that Stefan was actually the star athlete. He was popular, handsome, good in football, compassionate, yet a tough wall to break through. All of his teenage years, he stood to became the father figure for him and his sister since their father would always drink, day and night. Thus, Stefan becomes a good-boy-turned-bad.

Stefan is best friends with Donny Castillo and Mateo Ortega. He is romantically involved with Veronica Mizuno, the step-sister of his rival, Sebastian Young. He has an on-again, off-again friendship with Aurora Castillo and Phoebe McCartney; something to do with Veronica and his on-again , off-again interest in Aurora.