Simon Harper was the producer of Sentries of the Last Cosmos, an epic science fiction VR game very popular amongst teenagers.
Harper became immensely rich and popular, and soon he lost grip of reality and started to live out his own fiction. He created an empire themed around his franchise, and cast himself in the role of "The Great Wise One." In his private estate, Sentrycroft, Harper surrounded himself by high-tech machinery resembling of his fictional world.
Harper was bound by contract to share the profits of his game with its writer, Eldon Michaels, but when failed to do so, Michael sued Harper for 20% of the royalties. Harper then summoned the three highest score players and invited them to become real life Sentries. He convinced his deluded followers that his fictional world was real, and tricked them into doing his dirty work.
He sent them to Gotham's Hall of Records under the false pretense of a sacred mission. The Sentries believed they were going to destroy a databank infected by the "Dark Regent," while in fact they would be destroying his original contract with Eldon Michaels. However, Batman intercepted them and fought them off. He became suspicious of Harper and decided to confront him. At Sentrycroft, Harper casually denied any involvement in the attack to the Hall of Records. Then, he told his Sentries that Batman was an agent of the Dark Regent, who was in fact on earth under the human disguise of Eldon Michaels.
Harper sent his troops to do away with Eldon Michaels, though, they apprehended him instead. Furious, Harper blasted Michaels with arcing bolts hurling from his hands. At that point, Batman intervened and told his Sentries about the lawsuit, exposing Harper's charade. Harper tried to deflect him but Batman threw a bola at his hands, causing the electrical discharge to fry the suit's circuitry. Helpless, Harper ordered his Sentries to tackle Batman, but they turned on him. Harper was presumably brought before justice.
Simon Harper donned a special suit underneath his robes that allowed him to emanate electric bolts from his hands.