- Not to be confused with "Sins" (The Seven Deadly Sins)
Sin「シン」 is a mysterious talking fox.
Sin appears a normal fox with a coat of pink fur covering most of his skin except for his underside and the tip of his tail. He wears a collar with a small, crystal pendant around his neck and his eyes always appear closed.
Sin was shown to be blunt and straightforward in his conversation with Percival and Donny, after saving them from Pellegarde. At first, he showed no interest in Percival as he didn't bother speaking with him until he had reason to believe that the boy was one of the Four Knights of the Apocalypse, as he claims he is part of a group who opposes King Arthur and the Holy Knights of Camelot who hunt down for the four in hopes of preventing the prophecy of the world's destruction at their hands.
His attitude shows he approaches matter in a business-like manner and casually dismisses Percival's retort that he won't destroy the world, claiming that despite what the boy intends, it is destined to happen and cannot be prevented.