Who is mysterion is a question that has been asked many times. In the episodes “Coon vs Coon & Friends,” "Mysterion Rises," and "The Poor Kid" it is shown that Kenny McCormick is the alter ego of Mysterion, an otherwise oblivious superhero who can make objects appear. He can also jump off a building or second floor window with little to no pain as seen in the "Goth Kids" and "The Poor Kid" episode. He is also able to create illusions that are powerful enough to make the Coon and his friends take him seriously.
During this time, Cartman tried to guess who the superhero was. He narrowed down the suspects to two people – Kenny and Clyde Donovan. He also ruled out Bradley Biggle, who was not listed on Professor Chaos' wall nor accused by Cartman, and Stan Marsh because he is in the tool shed during coon 2.
Both Mysterion and Raven have an off-lavender basic suit with a bright green coloured "M" on the front. They both have a hood and robe-like cape or cloak covering their hair and face. Their feet are covered with brown boots. They both have two oval eyes with dark pupils and are average sized.
Mysterion is generally composed and methodical. He does not lose his temper often but will show emotion when he is taken seriously, as evidenced by the scene in "Coon vs Coon and Friends" where he urges Captain Hindsight to shoot him.