John Corben appeared as Metallo at the 9th Season of Smallville in three episodes. Savior, Metallo & Upgrade . The character was played by Brian Austin Green.
John Corben was a reporter who lived with his sister Rebecca before she moved to Metropolis. He was sent to cover a mission in Afghanistan and from there he kept in touch with his sister through video messages and reminded her to be careful because she was alone in the city. During this time, a truck carrying prisoners had a mishap and was rescued by the Blur but amid the commotion, a murderer managed to escape and ended up killing Becca. John was shattered by this news and returned from his trip to buy the building in which his sister lived. He blamed the Blur for what happened and since then he has been determined to expose him to the world.
John Corben was brought into the Daily Planet as a replacement for Clark Kent who was on indefinite family leave and went to the site of the recent monorail crash to investigate a story. He snuck inside to find Lois Lane looking for clues on the ninja who attacked her. Lois at first presumed he was a detective and tried to leave but Corben played along and questioned her. When a real cop saw the two, Corben kissed Lois and the cop presumed they were just passing civilians and told them to leave. Lois then smiled and stamped on Corben's foot. Corben later went to his desk opposite Lois' and began squeaking his chair and Lois thought it was Clark but saw Corben and still thought he was a detective but Corben revealed himself as a field reporter to replace Clark. Lois says that Clark will be back but Corben says he is on indefinite leave and shakes Lois' hand before leaving.
One night Corben was covering a story that involved the Blur and after talking with Lois and discussing his plans to expose the Blur for what he really is, he was run over by a truck. His bloodied body was found by Zod and his soldiers, who used him to try an experiment to regain their powers. Using stolen technology from LuthorCorp, they rebuilt Corben's body and transformed him into a cyborg with a kryptonite heart. He was abandoned in the building where the surgery took place and after waking was confused and afraid by what had happened to him. He was transported to the Metropolis General and attended to by Dr. Hamilton who informed him that the implants were what had kept him alive. In a fit of psychosis, John gets up scared, and discovered that he now had super strength, and escapes leaving an orderly in a coma. His adrenaline level started to rise clouding his mind making it think that what happened was a gift to kill the Blur for what he had done to his sister. He attempted to track the Blur using the Daily Planet archives, and there he meets Lois, who gives him her key to the Planet's archives room. Realizing that Corben is the man who ran wild at the hospital earlier in the day before fleeing, Lois goes to a phone booth and speaks to the Blur. However, John realizes that Lois had contact with the Blur and decides to kidnap her to find out what she knew. He takes her to the basement of the building in which he lived and after Lois' refusal to collaborate with him, he sent her flying through a wall. Clark appears at that time and tells John that he regretted what had happened to his sister. Corben refused to accept the apologies, and then Clark set off an electromagnetic pulse grenade and momentarily disabled the cyborg. Corben restarted instantly and prepared to kill Lois. Unable to approach the cyborg because of the radioactivity of the kryptonite, Clark heated a lead plate and slammed it into Corben's chest. Realizing the weakness of the Blur, Corben tried to expose his kryptonite heart by ripping the lead plate from his chest, but in the attempt, the meteorite rock stuck to the plate, leaving Corben without power and shutting him down.
At a later point, Tess Mercer received an update on Corben, who had apparently been "repaired". However, the operations have left him more machine than man, also leaving no vital signs. Later, when Tess visited Winslow Schott, a mad criminal genius who used to work for Lex, she gave him John's kryptonite heart for him to tinker with in an attempt to see if he could help reboot John's systems.
