It s made quite clear towards the end that Kyle is the Human Kite The first clue is that Cartman deliberately mispronounces his name at the beginning as The Human KYKE a common slur against Jews Likewise the Human Kite has the same voice as Kyle s only a little deeper which is to be expected as pretty much ALL of the boys deepen their voices while in costume As for Mysterion and Mosquito Kenny or Clyde can be either one of them until definitive proof can be found Also Mintberry Crunch is very obviously Bradley