WARNING: The following article contains spoilers for Batman #110 by James Tynion IV, Jorge Jimenez, Tomeu Morey, Clayton Cowles, on sale now.

Batman's villains have frequently been sent to Arkham Asylum, but Harley Quinn has the distinction of being the only major member of his rogues gallery who was both a patient and a licensed staff member at the criminal asylum. However, another former Arkham employee recently became one of Batman's most dangerous villains, the sadistic guard Sean Mahoney, now known as Peacekeeper-01.

All the records from Arkham Asylum were recently lost, but Harley Quinn remembers Mahoney, and she was not shy about giving her thoughts on the man. She was horrified by his wanton cruelty--and that is saying quite a bit, as she dated the Joker for years. In fact, she was even willing to offer a personal diagnosis on his mental state.

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Peacekeeper-01 Batman

The Peacekeepers are a high-tech militarized private police force best known for wantonly killing both criminals and civilians during DC's "Future State" event. They worked for an organization known as the Magistrate and were formed by the tech magnate Simon Saint, who hoped to use them to assert more control over Gotham. While the Peacekeepers initially appeared in the near future stories of the event, Batman fought against one for the first time in the present day during his confrontation with Peacekeeper-01 in issues #109-110 of the Caped Crusader's self-titled series.

This fight did not go well for the Dark Knight. The Peacekeeper armor was designed to analyze and respond to every combat maneuver and gadget that Batman could employ. Worse, Peacekeeper-01 proved how sadistic he was when he stated that he was only interested in killing the Caped Crusader, and had no intention of even trying to arrest him. He accused the Dark Knight of making the city more dangerous by provoking supervillains to attack and denounced him for working alongside criminals like Harley Quinn and Catwoman. He berated the Gotham City vigilante further for partnering with former police commissioner Jim Gordon, who he referred to as a "turncoat cop-hater." He never explained his reason for thinking Gordon hated the police, but this line is quite revealing about the villain's particular pathology. He sees anyone who deviates from his view of the world as aberrant and therefore deserving of death.

Throughout the fight, Peacekeeper-01 openly boasted that he planted bombs in Gotham's city hall to help Simon Saint gain power. Gotham's police department would need help responding to this bombing and he anticipated them turning to the Peacekeepers for support. The sadistic villain committed an act of domestic terrorism and lied about it, because he thought it was the only way the Peacekeepers could help keep Gotham safe from terrorists and other violent criminals. Making matters worse, the Peacemaker armor proved to be more than Batman could handle, and the Dark Knight was forced to flee.

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Batman Harley Quinn Peacekeeper

Back in his hideout, Batman spoke to Harley about his fight. She remembered Peacemaker-01 from back when he was just Sean Mahoney, working as a guard at Arkham. He regularly was in trouble for abusing the inmates, and Harley described him as a "sadist" who had "insecurities in all the wrong places." When she learned that all records of Mahoney's misconduct at Arkham had been lost and that he had been hired to help protect the city, Harley was appalled.

It is certainly questionable to give Mahoney a job as Peacekeeper-01. He is a repeat offender with a documented history of violent crime. But possibly because of his position at Arkham, he was never prosecuted. As the head of the Peacekeepers, he once again is in a position of authority, and terrorist bombings are just one of the ways he is abusing his power.

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