SPS FAQ.
Очень занятное место, да. Я теперь знаю, секрет цвета глаз, и то, что Пип сдох с концами (блин, как они могли замочить пацана, которого юзали еще до ЮП?! Ну, блин, Сволачи же ж!). Ну и Мистерион, забавно, да:

вопрос:
who the hell is mysterion??????

ответ:
Dearest fans,

This question has been asked about a billion times -- and as I've mentioned before, THERE IS NO DEFINITE ANSWER. I wish I could tell you who Mysterion in, but I'm seriously. I have no idea. Matt and Trey are the only ones on the entire staff that have this knowledge, and they don't seem to want to give it up.

BUT here's the clues I've gathered from that episode: It's one of the kids in Mr. Garrison's class and it's not Kyle, Cartman or Butters (because all of them are in a scene together with Mysterion). Also, Clyde was sleeping in class...don't know if that's a clue or if Cartman's Coon presentation was just that boring. And lastly, after Mysterion is "revealed", Cartman says he guessed the kid's identity earlier. The only kids he called out directly were: Craig, Kyle (it's not him), Stan, Clyde, Kenny, and Wendy...kinda.

So there. That's all I know. I'm super cereal.