Arnie was terribly scarred in his youth in an unknown event and left in a coma. When he came to, he eventually sought out the X-Statix, telling them he was their biggest fan ever, but not before using his powers to take over a town completely by force. He was especially fond of U-Go Girl, and claimed that it was her who lead him out of his coma. Although he was obviously a huge fan of the X-Statix, he blamed Orphan for killing his favorite member. It was never revealed who that member was.
Mysterious Fanboy was created by Mike Allred and Peter Milligan and first appeared in X-Statix issue 1 (2002).
Major Story Arcs
In his anger at Orphan, Arnie summoned an army of zombies to assault a branch of the X-Statix spinoff team, the O-Force. Orphan attempted to stop Arnie, but was utterly defeated at the hands of Arnie, ultimately being thrown out a window into a mass of the zombies. Orphan would have been ripped to shreds had the other X-Statix not saved him. Orphan convinced Arnie to utilize his powers to stop what he had begun, and Arnie reluctantly complied. After those events, Arnie was nominated by the Orphan for team membership so that he could watch him, and make sure he didn't do anything evil. When Arnie joined the X-Statix, he put on his mask and adopted the guise of Mysterious Fanboy. Because he was so self-conscious of his scarred appearance, Lacuna used her powers to take off Arnie's mask on live television, causing the X-Statix's overall ratings and popularity to quickly rise. In Arnie's last mission, he managed to kill the "indestructable" Razorhead and save the team before he was dying of a heart attack. It was later revealed that the heart attack was induced by an injection given to him by Lacuna under the orders of the Orphan.
Arnie was a very powerful mutant who, similar to the Scarlet Witch, could manipulate reality for a wide variety of effects. He also showed the ability to teleport himself and other objects at will. One of his most popular displayed abilities was the animation of deceased beings, rendering them undead slaves to anyone he chose. Although these are the only abilities he displayed (besidese matter manipulation), it is believed that due to his reality-bending power, he had the capabilities to manipulate nearly any other power he wished.