Purgatory

Paul Christian was an average New Yorker who had lost his legs in a subway accident years before an accidental meeting with Kyle Rayner changed his life.  
 
During an otherwise uneventful day, the Green Lantern found himself in the middle of a battle with a low level thug who had acquired a suit of battle armor. Paul was wheeling his chair outside of the NY Public Library when a stunned Kyle Rayner crashed into him, knocking him from his chair.  
 
After Kyle stopped the thug, he apologized to Paul and the two began talking. Intent on being more then just a "beat the bad guy" hero, Kyle passed on a small portion of his power to Paul, allowing the disabled man to will himself a pair of energy crafted legs. Paul was overjoyed over the prospect of walking again and thanked the Lantern as Kyle flew off.  

 
Now mobile, Paul traveled to the Statue of Liberty and happily began climbing up the stairs to the observation tower. During the climb he accidentally cut his hand on a broken rail, momentarily distracting his willpower. Paul's constructed legs disappeared. Once again disabled Paul ominously vowed to never lose his focus again.   
 
Shortly after the incident, Paul managed to sufficiently reassert his willpower so that his "legs" returned. Arriving at his home, he discovered an intruder inside his house. The demon Neron was actively trading power to anyone who would wreak havoc on the earth. Neron offered Paul enough power to sustain his legs permanently. in exchange, he demanded that Paul destroy Kyle Rayner. A desperate Paul accepted the demon's bargain, becoming the demonically powered being now known as Purgatory.  
 
Able to wield powers similar to the Green Lantern, Purgatory attacked Rayner and the Darkstar Donna Troy while the two were battling a similarly demon power Mr. Freeze in 's . After a pitched battle, Rayner managed to slam Purgatory into Mr. Freeze knocking out the master of cold. Although beaten, Purgatory managed to slip away and avoid capture. 

Purgatory resurfaced shortly thereafter. He was found in an alley by two NYPD officers. Purgatory seemed reluctant to kill the cops and ordered them to flee before he hurt them. As the two officers ran, Purgatory questioned what he had become. His doubts were interrupted by the return of Neron who was furious that Paul had failed to live up to his end of the bargain and kill Kyle Rayner.  
 
Overcome with emotion, Paul angrily accused Neron of tricking him into becoming something less then human. All Paul wanted was to walk again; denouncing Neron Paul insisted the demon take back his power. However Neron reminded his victim that this was not part of their bargain. Neron attacked Paul with an agonizing blast of energy and threatened to drag him to hell where he would endure such suffering for eternity. Writhing in pain, Paul reluctantly agreed to do as Neron asked and destroy Green Lantern.  
 
 Purgatory tracked Rayner and  back to Kyle's apartment. Blasting through a wall Puratory attacked Kyle with renewed focus. Desperate but ashamed, Purgatory tried to explain his actions to Kyle. He told the Kyle about his deal with Neron and how he would be dragged to hell if he didn't kill the Lantern.  
 
While Darkstar cleared Kyle's build of civilians, Kyle attempted to beat his foe by overloading Purgatory with a tremendous amount of energy straight from his battery. The tactic worked, and Purgatory was restored to his human form, freed of the demonic energy Neron had granted him. Paul was happy to be free of the demon but his joy was short lived. Having failed his master, Paul was slowly teleported to Neron's realm. Presumably, he remains there as another of the tortured souls who foolishly bargained with the malevolent demon.