Fan Casting Unwitting Pawn in Sort by Tropes

This is the kind of person that the Magnificent Bastard and Batman Gambit depend on. Not only does an Unwitting Pawn fail to stop the bad guy, but he actually furthers the villain's plan in the process. The Manipulative Bastard will take great delight in using them and then deconstructing their naivete and blind faith as they gloat (in which case compare What Have I Done). Not surprisingly, they also have a tendency to die ironically after inadvertently helping the villain. But if they survive... there's bound to be some nasty surprises in store for the Bastards.