clyde i thought it was stan cause he visited kyle in his room

But satn and Mysterion were in the same scene at one point :p

i think its stan
second guess: clyde

Stan is definitely Mysterion.

clyde total check the facts

Freaking Dickholes! >.<
It's STAN! How could Clyde get illigal fireworks ANYWAY?!
Haha, there is very clear evidence it might be Clyde, but there is even MORE evidence it's Stan, so duh, it's Stanley Marsh :P

Wow. People saying it is stan, that is impossible. Stan is tool shed. In episode: Coon 2:Hindsight, Stan was sitting across the table from mysterion as tool shed. The berry crunch mint guy is some random kid ive never seen, so rule him out. Rule out cartman. Rule out kyle, because mysterion talked with him in the first episode with mysterion. Mysterion is white. So rule out Token. Rule out butters, hes evil.

Following kids who ARE super heros: Clyde, Timmy, Token, Cartman, Stan, Kenny, Kyle, Random kid.

So all we have left is: Clyde, Timmy, Kenny.

It cant be timmy, he is in a wheel chair.
So we have Clyde and Kenny. Judging by the super hero with the kite on his back, his voice sounds EXACTLY like clydes. And mosquito kid is just a random kid that has no real potential, like a random character for fun. The mosquito kid isnt even there when their out of their costumes. So it is obviously, Kenny. Wendy isn't even in the part with them and their costumes off. So it isnt her. So it is obviously, Kenny.