Devilicus was really a young boy named Alec Abrams who was cursed by a magical comic book in the CW TV series Smallville.
He served as the main antagonist in the Season Nine episode "Warrior".
Alec was portrayed by Owen Best, who also played a young Jason Teague in the same series and Devilicus was portrayed by Carlo Marks.
Alec Abrams lost both of his parents when he was young and went to live with his aunt. At school, Alec was often bullied by the other kids and never believed in heroes until the Red Blue Blur appeared in Metropolis. Alec began admiring the superhero and often dreamt of meeting him in person. He wrote letters and sent them to the Daily Planet in hopes of getting his attention. Alec became convinced that his life would be perfect, if he was a superhero.
At the Metropolis WonderCon, Alec Abrams admires a rare Warrior Angel comic book, and asked the worker if he could take a look at it, but the worker tells him that opening the book will lower its value. However, the worker then unlocked the case to check it, and when he is distracted by a man knocking over the comic display, Alec took the opportunity to run off with the book. What Alec wasn't aware off, was that the comic had a curse on it.
When he read it, magical sparks flew out causing Alec to transform into the grown Warrior Angel. In the convention hall, the lights went out and a giant globe fell, directly above Chloe Sullivan but was caught by the now adult Alec who rescued her. When Chloe properly meets him, he introduces himself as Stephen Swift. Chloe explained that she was in the business of helping heroes and offers to talk some more over coffee.
When Chloe questioned how he got his powers, he told her he got them from a chemical fire. He then heard a couple of bullies harassing a young boy in an alley way and went to save him while Chloe looked on in amazement. Chloe took Stephen to the Talon, where Stephen was playing happily on Lois' Xbox, while Chloe attempted to interview him. Stephen counters that Chloe never lets herself have fun, and that if she joins him in playing, he will answer her questions.
She agrees, and as he lists his powers, he rises slowly into the air, surprising both of them. Excited by the idea that he can fly, Stephen takes Chloe on a moonlight flight across Metropolis. Chloe went to the Watchtower where Clark and Zatanna used the resources to track down Alec. After being updated to speed, Chloe realizes that Stephen is really little Alec, so she rushes off to try and help him before Zatanna can reverse the spell.
Chloe confronts Stephen about the source of his powers, and explains that Zatanna plans to undo the curse. Feeling betrayed by this news, Stephen morphs from the sweet young man, to a demonic version of himself. He proceeds to take Chloe to the top of a skyscraper demanding that Chloe tell him where Zatanna is, so he can stop her, or else he will kill her.
When Zatanna performed the counter-curse, Devilicus was transformed back into Alec. Unfortunately, the force of the magical blast throws Chloe off the rooftop, but thankfully the Blur is there to catch her and the two return to the rooftop, to find little Alec huddled in tears.
Clark took Alec back to the farm, where he explains that being a hero is not about powers, but rather doing the right thing. Alec feels guilty for becoming a bully, but Clark says that not all bullies are bad people, and can still have good inside them. Appreciating Clark's advice, Alec offers Clark a picture he drew when Clark was still the "Red & Blue Blur". The two smile as they mutually agree that the 'S' shield is a better design than the one on Alec's drawing.
Clark returns Alec to the Daily Planet, where he was reunited with his aunt and Zatanna has gotten the charges against Alec dropped.